SPOILER ALERT!
I just played the game for an hour or two, I got about 90% of the outfits, and a reasonable amount of upgrades. I struggled with the red giant robot a bit. When I killed it, there came an instant screen with Uncle Sam with a cat head with a text under it saying: "Thank YOU for playing! You are the best!"
I cannot exit the screen without closing the game.
Well, that was a unintimdating ending.
Otherwise, the only thing that kept me playing this over 5 minutes was getting all the outfits. That is a thing I can thank the devs, for making something that keeps you playing. The outfits are randomized in order, but in inventory, the same place has always the same buff.
The game is not really an idle game, because when you lose, the game doesn't start over on it's own. You need to do actions for the game to progress.
It's also a great addition that when you kill a squad of non-outfitted raccoons, they run away. Easier progression.
I have not played the other two games, but from what I saw in this one, I don't expect a great amount of difference. The idea is easily clonable.