Objectives: A Roadmap for This Game

Objectives (the in-game version of Steam Achievements) are there for a reason. Unlike many games that put ridiculous criteria for theirs, Heli-Cats uses this as a roadmap for players to explore all the game has to offer. The descriptions give hints about what is waiting and how to get there without spoiling the experience.
For example, the objective seen above for Ending A reads "Destroy arcade mode's mission 8 boss with continues", which can logically be inferred that there is something else that happens if done without using continues. Since another objective hints of a mission 9, this solves one of the entry requirements to that elusive frontier. A no continue run? Sounds impossible?
Not to worry. Heli-Cats is a game that rewards expert gameplay yet also accommodates players of lower skill. So there is always another way to attain difficult objectives. The other mission 9 entry requirement that allows continues is again related to another objective, but this one is not as obvious as it seems. Remember, the game ultimately encourages players to improve by doing things beyond credit feeding.
Try to figure out what that other criteria is before it is posted here!
Hint: The game completely opens up once mission 9 is breached and subsequently beaten (continuing is allowed so have some spare credits to be safe). It may be worth it to use the continuing method if a 1CC is too challenging.