Developer Diary #23 | Swimming Horses, Design Pillars, Breeding Update!
Dear Couriers, we have a lot of topics to cover today, because this is our last dev diary before the Early Access launch, aaaaaaaah! Bear with us, it’s all very exciting!
First of all, we have exciting news about a feature we’ve been working on the past weeks. We did not want to announce this before we were confident that we’d actually be able to implement it to everyone’s satisfaction, but now that we’re far enough along in the process to actually show you, we’re very pleased to reveal: Horses in The Legend of Khiimori will be able to swim!
Explore 13th‑century Mongolia… on a swimming horse!
[h2]What to Expect from Swimming[/h2]
While all horses can swim in the game, that doesn’t mean that rivers and lakes just suddenly don’t constitute obstacles anymore. Instead, traversing bodies of water will become another way of interacting with our game world that intertwines with many of our existing gameplay systems.
What does that mean for the player?
Swimming Horse GIF
[h2]Game Design Philosophy[/h2]
To give you a bit of additional insight as to why this choice was made — alongside the various other improvements and fixes we’re investing our extra time into — let’s recap what we think of as the four main pillars of our game. Design pillars are the foundation any big game project is built upon, and reminding ourselves of these pillars is how we decide which features are worth adding and which are not really suited to our core vision.
So what are the four core design pillars that The Legend of Khiimori is built upon?
1. Authentic Horses and Equine Realism
Horses are not just mounts in The Legend of Khiimori they can also be thought of as “tools”.
We are putting extraordinary care into capturing the authenticity of Mongolian horses: their endurance, temperament, and the deep cultural bond they shared with riders of the era. Horses respond to exhaustion, hunger, terrain, and care. Your relationship with your horse grows over time, influencing handling, trust, and survival in the open wilds.
Lose your horse, mistreat it, or push it too hard… and life on the steppe becomes far more dangerous.
2. Believable Setting and 13th Century Mongolia
The open world of Khiimori is inspired by real landscapes, climates, and nomadic cultures of 13th century Mongolia. Vast grasslands, sacred sites, trade routes, river crossings, and harsh weather all shape how you move and survive.
There are no convenience markers or theme-park shortcuts. Instead, the land itself tells stories—through ruins, camps, trails, and the people you meet along the way.
3. Vivid Open World and The Life of a Courier Rider
In The Legend of Khiimori you are a courier rider, carrying messages, goods, and knowledge across an untamed world. Distance matters. Time matters. Preparation matters.
Each journey requires planning:
The open world is designed to reward observation, memory, and mastery, making every successful delivery feel earned.
4. Enjoyable Mechanics and Survival Elements
Survival in Khiimori is challenging, but never tedious.
We are building systems that are deep, readable, and respectful of your time. Food, warmth, exhaustion, and equipment condition all play a role, but they are designed to support immersion.
Every mechanic exists to reinforce the fantasy of being a rider struggling against nature, scarcity, and distance, rather than fighting menus or micromanagement.
Where will your deliveries take you?
[h2]Adding Richness to Traversal[/h2]
We’ve been closely listening to the feedback we received from our Next Fest Demo, played by over 50.000 people, and the Alpha Playtest for Kickstarter backers, played by about 4.000 people, who are very passionate and have invested hours and hours into the game already. Horse Swimming is something many of you have asked for, so it made sense for us to explore and find out not just how technically feasible it was, but if it would fit into the aforementioned design pillars.
1. Horses can swim in real life, and they can be trained to swim with a rider → that fits our goal for authentic equine representation
2. For Mongolian nomads, horses were the form of transportation, carrying riders across all terrain. We found historical sources from the 13th century describing the ways Mongolian riders would cross rivers with their mounts → swimming horses thus fit into our intentions for a believable historical setting
3. Route planning and weighing risks against rewards is already a core element of our game, and applies to various aspects from dangerous wildlife, to harsh weather conditions, to treacherous ground types. Adding water crossing fits neatly into those systems → that makes it a perfect fit for our vivid open world and courier rider gameplay
4. Swimming comes with limitations — remember the stamina drain and water-sensitive cargo we mentioned above — that add meaningful challenges to our survival and traversal gameplay. At the same time, making some rivers and lakes cross-able on horseback adds another way of interacting with the level and potentially reducing frustration of having to take a long way around. Meaning → this suits our goal of providing enjoyable mechanics and survival elements really well.
This thought experiment of fitting a feature into the design pillars may strike you as overly theoretical, especially if you find it obvious that horses in a game should be able to swim for the sake of fun and realism. But with hundreds and thousands of feature requests from players reaching us, it’s important to us that we listen with a critical ear and make sure that a new mechanic really fits into our vision of the game before we invest the precious time of our coders, animators and technical artists to bring that feature into the game.
Plan your routes wisely!
[h2]An Update from the Breeding Paddock [/h2]
We’ve talked about our horse breeding feature before, but we wanted to share some cool updates on this topic. As you can see, we’ve overhauled our breeding UI quite extensively to make it clearer what your foal is inheriting from its parents and what you might be able to influence.
If you’re the kind of horse nerd that already got excited about seeing Extension and Agouti and Dun genes explicitly listed here (and we know we are!), we don’t need to explain to you why this is cool. For anyone else though, let us remind you that horse breeding is one of the core avenues of progress in The Legend of Khiimori. Think of your stable of horses as the party in your RPG, the Garage full of race cars, the arsenal of weaponry, where each steed is suited for particular purposes and upgrading (training and breeding) them over time is what lets you traverse the world more easily, reach places you weren’t able to reach before and take on more difficult missions.
Horses in The Legend of Khiimori are not just adorable companions (though they are very much that too!) but also specialized tools that allow you to do your job as a Yam courier rider.
Select a mare and a stallion…
…check possible outcome…
…apply blessings for optimized breeding.
[h2]Starting Into Early Access[/h2]
We’re just a week away from releasing into Early Access on March 3rd, 2026, and can’t wait for all of you to try the game for yourselves! As we’ve said before, the Early Access release is just the next step on our journey together, not its destination, so we’re looking forward to your feedback and your enthusiasm to help us fit the game into the vision you as players and we as developers share.
When the game releases, please consider that by leaving a Steam review very soon after release, you’re doing a huge service to the game to increase its visibility in the store. By reviewing games quickly and generously, you’re actively helping us gain more traction, which in turn helps us invest more time into improving the game. We know the game won’t be perfect yet - that’s the point of Early Access after all, to improve it with your input! - but positive reviews are actually more helpful towards getting improvements made in the long run than negative ones, which risk getting the game buried in the Steam algorithm.
Also, on the day of launch, we will be holding an Early Access Launch Livestream at 3 PM CET / 6 AM PST with interesting guests and all that is Khiimori: AesirInteractive - Twitch
Tune in on March 3rd, 2026!
So, what do think about this? Do you have any additional questions or feedback for us? Please drop us a message right here or on one of our Social Media channels!
Your Team at Aesir Interactive
PS: The Early Access release of The Legend of Khiimori on March 3rd, 2026, is only the beginning! More features and content will be added throughout Early Access. Make sure to check our Trello board to see what we’re currently working on and which content and features are coming next: The Legend of Khiimori - Development Roadmap
One last jump and we launch!
[hr][/hr][h3]Previous Developer Diaries can be found here:[/h3]
[hr][/hr][h2]Join the Community[/h2][p]Bluesky Facebook Instagram Threads TikTok Twitter
Discord Twitch YouTube Website[/p]
First of all, we have exciting news about a feature we’ve been working on the past weeks. We did not want to announce this before we were confident that we’d actually be able to implement it to everyone’s satisfaction, but now that we’re far enough along in the process to actually show you, we’re very pleased to reveal: Horses in The Legend of Khiimori will be able to swim!
Explore 13th‑century Mongolia… on a swimming horse![h2]What to Expect from Swimming[/h2]
While all horses can swim in the game, that doesn’t mean that rivers and lakes just suddenly don’t constitute obstacles anymore. Instead, traversing bodies of water will become another way of interacting with our game world that intertwines with many of our existing gameplay systems.
What does that mean for the player?
- Swimming drains your horse’s stamina quite quickly, so attempting a water crossing brings a bit of risk. If you can reach the same point via dry land, that may be the safer route, even if it’s the long way around.
- Some of the cargo you transport isn’t exactly water-proof. Taking a shortcut through a river may therefore only make sense if you’re in between missions, or carrying something that won’t get water-damage.
- How long your horse can swim depends on its stamina and robustness. Through training, you are able to increase the distances your horse can swim, thereby potentially opening up new routes for yourself.
- Islands in lakes and rivers may contain rewards or collectible items that aren’t otherwise easy to reach, so taking a detour to these places may well be worth a dip in the water – provided again that you’re not carrying water-sensitive cargo or risking your horse’s health in the process.
Swimming Horse GIF[h2]Game Design Philosophy[/h2]
To give you a bit of additional insight as to why this choice was made — alongside the various other improvements and fixes we’re investing our extra time into — let’s recap what we think of as the four main pillars of our game. Design pillars are the foundation any big game project is built upon, and reminding ourselves of these pillars is how we decide which features are worth adding and which are not really suited to our core vision.
So what are the four core design pillars that The Legend of Khiimori is built upon?
1. Authentic Horses and Equine Realism
Horses are not just mounts in The Legend of Khiimori they can also be thought of as “tools”.
We are putting extraordinary care into capturing the authenticity of Mongolian horses: their endurance, temperament, and the deep cultural bond they shared with riders of the era. Horses respond to exhaustion, hunger, terrain, and care. Your relationship with your horse grows over time, influencing handling, trust, and survival in the open wilds.
Lose your horse, mistreat it, or push it too hard… and life on the steppe becomes far more dangerous.
2. Believable Setting and 13th Century Mongolia
The open world of Khiimori is inspired by real landscapes, climates, and nomadic cultures of 13th century Mongolia. Vast grasslands, sacred sites, trade routes, river crossings, and harsh weather all shape how you move and survive.
There are no convenience markers or theme-park shortcuts. Instead, the land itself tells stories—through ruins, camps, trails, and the people you meet along the way.
3. Vivid Open World and The Life of a Courier Rider
In The Legend of Khiimori you are a courier rider, carrying messages, goods, and knowledge across an untamed world. Distance matters. Time matters. Preparation matters.
Each journey requires planning:
- Which route is safest?
- Do you risk a shortcut through hostile terrain?
- Can your horse make the trip without rest?
The open world is designed to reward observation, memory, and mastery, making every successful delivery feel earned.
4. Enjoyable Mechanics and Survival Elements
Survival in Khiimori is challenging, but never tedious.
We are building systems that are deep, readable, and respectful of your time. Food, warmth, exhaustion, and equipment condition all play a role, but they are designed to support immersion.
Every mechanic exists to reinforce the fantasy of being a rider struggling against nature, scarcity, and distance, rather than fighting menus or micromanagement.
Where will your deliveries take you?[h2]Adding Richness to Traversal[/h2]
We’ve been closely listening to the feedback we received from our Next Fest Demo, played by over 50.000 people, and the Alpha Playtest for Kickstarter backers, played by about 4.000 people, who are very passionate and have invested hours and hours into the game already. Horse Swimming is something many of you have asked for, so it made sense for us to explore and find out not just how technically feasible it was, but if it would fit into the aforementioned design pillars.
1. Horses can swim in real life, and they can be trained to swim with a rider → that fits our goal for authentic equine representation
2. For Mongolian nomads, horses were the form of transportation, carrying riders across all terrain. We found historical sources from the 13th century describing the ways Mongolian riders would cross rivers with their mounts → swimming horses thus fit into our intentions for a believable historical setting
3. Route planning and weighing risks against rewards is already a core element of our game, and applies to various aspects from dangerous wildlife, to harsh weather conditions, to treacherous ground types. Adding water crossing fits neatly into those systems → that makes it a perfect fit for our vivid open world and courier rider gameplay
4. Swimming comes with limitations — remember the stamina drain and water-sensitive cargo we mentioned above — that add meaningful challenges to our survival and traversal gameplay. At the same time, making some rivers and lakes cross-able on horseback adds another way of interacting with the level and potentially reducing frustration of having to take a long way around. Meaning → this suits our goal of providing enjoyable mechanics and survival elements really well.
This thought experiment of fitting a feature into the design pillars may strike you as overly theoretical, especially if you find it obvious that horses in a game should be able to swim for the sake of fun and realism. But with hundreds and thousands of feature requests from players reaching us, it’s important to us that we listen with a critical ear and make sure that a new mechanic really fits into our vision of the game before we invest the precious time of our coders, animators and technical artists to bring that feature into the game.
Plan your routes wisely![h2]An Update from the Breeding Paddock [/h2]
We’ve talked about our horse breeding feature before, but we wanted to share some cool updates on this topic. As you can see, we’ve overhauled our breeding UI quite extensively to make it clearer what your foal is inheriting from its parents and what you might be able to influence.
If you’re the kind of horse nerd that already got excited about seeing Extension and Agouti and Dun genes explicitly listed here (and we know we are!), we don’t need to explain to you why this is cool. For anyone else though, let us remind you that horse breeding is one of the core avenues of progress in The Legend of Khiimori. Think of your stable of horses as the party in your RPG, the Garage full of race cars, the arsenal of weaponry, where each steed is suited for particular purposes and upgrading (training and breeding) them over time is what lets you traverse the world more easily, reach places you weren’t able to reach before and take on more difficult missions.
Horses in The Legend of Khiimori are not just adorable companions (though they are very much that too!) but also specialized tools that allow you to do your job as a Yam courier rider.
Select a mare and a stallion… …check possible outcome……apply blessings for optimized breeding.[h2]Starting Into Early Access[/h2]
We’re just a week away from releasing into Early Access on March 3rd, 2026, and can’t wait for all of you to try the game for yourselves! As we’ve said before, the Early Access release is just the next step on our journey together, not its destination, so we’re looking forward to your feedback and your enthusiasm to help us fit the game into the vision you as players and we as developers share.
When the game releases, please consider that by leaving a Steam review very soon after release, you’re doing a huge service to the game to increase its visibility in the store. By reviewing games quickly and generously, you’re actively helping us gain more traction, which in turn helps us invest more time into improving the game. We know the game won’t be perfect yet - that’s the point of Early Access after all, to improve it with your input! - but positive reviews are actually more helpful towards getting improvements made in the long run than negative ones, which risk getting the game buried in the Steam algorithm.
Also, on the day of launch, we will be holding an Early Access Launch Livestream at 3 PM CET / 6 AM PST with interesting guests and all that is Khiimori: AesirInteractive - Twitch
Tune in on March 3rd, 2026!So, what do think about this? Do you have any additional questions or feedback for us? Please drop us a message right here or on one of our Social Media channels!
Your Team at Aesir Interactive
PS: The Early Access release of The Legend of Khiimori on March 3rd, 2026, is only the beginning! More features and content will be added throughout Early Access. Make sure to check our Trello board to see what we’re currently working on and which content and features are coming next: The Legend of Khiimori - Development Roadmap
One last jump and we launch![hr][/hr][h3]Previous Developer Diaries can be found here:[/h3]
- [p]#02 | An Open World[/p]
- [p]#03 | PC Early Access[/p]
- [p]#04 | Horse Training and Horse Care[/p]
- [p]#05 | All Eyes on Khiimori[/p]
- [p]#06 | Cantering towards Crowdfunding[/p]
- [p]#07 | Looking Forward to Next Year[/p]
- [p]#08 | Updates from the Steppe[/p]
- [p]#09 | Survival on Horseback[/p]
- [p]#10 | Early Access Expectations[/p]
- [p]#11 | Thousands of Bugfixes and Other Improvements[/p]
- [p]#12 | Join Us at Gamescom! (and Other Updates!)[/p]
- [p]#13 | EA Release Date, Gameplay Trailer & Gamescom Highlights[/p]
- [p]#14 | News about Game’s Title, Languages & Alpha Playtest Survey[/p]
- [p] #15 | Breeding in our Demo, Performance Considerations & More[/p]
- [p]#16 | Our Updated Roadmap to Early Access[/p]
- [p]#17 | 2025: A Year in Review[/p]
- [p]#18 | Taming the Open Wilds of 13th Century Mongolia[/p]
- [p]#19 | Early Access Launch Features & Roadmap[/p]
- [p]#20 | Courier Video & New Key Art[/p]
- [p]#21 | Spirit Combat & Corrupted Zones[/p]
- [p]#22 | Soundtrack Making-of[/p]
[hr][/hr][h2]Join the Community[/h2][p]Bluesky Facebook Instagram Threads TikTok Twitter
Discord Twitch YouTube Website[/p]