Oof, i might have to code in some cheats so i can get that far into the game to see how this happens lol. Stay tuned
Same thing is happening here. The helicopters made the game easier. Helicopters keep crashing into each other & blowing up their own tanks. The more helicopters & tanks they lose, they double-down & send even more in, destroying more of themselves in friendly fire.
I do realize this makes it a highly accurate simulation of Russia's battle competency though.
I think the helicopters & pickle jars come into the game too early, maybe don't send the first helicopter until the player gets 10 tanks? Maybe cap the number of hearts & tanks on the field at once? My machine slows down to 1 FPS once there's too many hearts.
(Love the game though! The pre-helicopter version had a Flappy Bird feel, bite-sized game length & even 8 tanks felt like a high score!)