Game features:

Automatic synthesis, acceleration, double gold coins, special effects let you go through levels on-hook
Collect various cards to gain group buffs and boss life debuffs
Leaderboard function, compete with other players
This is a free game, and will not actively pop up ads, will not affect the game experience
The game does not need internet, you can play boss at any time
Various characteristic attack turrets form interactive firepower
Green turret: the farthest attack range
Red turret: splash damage
Yellow turret: laser sweep
Blue turret: range slowdown
Accumulate energy for air support
The difficulty of more than 2000 levels is gradually increasing. I don’t know what will appear at the end of the game.