Update 18.0

Fixed calling artillery
Increased aircraft speed, reduced cost of calling it
Lumberjacks no longer swing their axes through the air
Trees fall after being cut, rather than simply disappearing
Optimized visual effects
Added new sound effects
Small decor sprites, bullets, shells, sparks, etc. have been redrawn.
Increased rate of fire of anti-aircraft guns
Concrete blocks and steel beams shatter into pieces when destroyed
Increased gun accuracy
Fixed bug with eagle
Added survival mode with huge enemy onslaught
Added 3 achievements to survival mode