Really cool idea with decent gameplay. I really like that we play as the mokey from donkey kong. The gameplay is you mostly doing nothing while waiting for the explosion cooldown to finish and choosing upgrades but i guess that's just how tower defense games are. There are no sounds in the game which is a shame since you could easily make sound effects with sfxr and implement to the game to increase the feel of the game a lot. The satisfaction of these type of games usually come from all of the sound effects. The main menu is very simple which is fine but at least you could have changed the font. Without a font the game looks and feels very unfinished. And also if what you said on the description is true and the difficulty increases infinetly that means there will be a point in the game where you are forced to lose because the upgrades are limited so there will be a point in the game where the enemies get stronger but you don't. But overall really cute game and would love to see a full version! Good luck on you'r future project's!