Super fun game! I love these kinds of games, it's very reminiscent of Battle Panic by Ninjakiwi in the early 2010s. Glad Markiplier took his time to give this exposure. Very fun loop. Definitely more things could be added in the future, but it's very solid and repeatable. You could absolutely add new mechanics and enemies onto this, and maybe some synergies between classes would be great. Challenge levels, secrets, bosses, more things to do with the cursor like heaing, etc. etc. So much potential.
While I figured the lamps from the upgrade tree, the only issue I saw gameplay wise is that 1. there is a finite amount of lamps you can build, meaning you might have to play a level a few times to get all the eggs (though I'm not too sure about cues where to place them, and that's not too difficult in the early levels anyway) and 2. there seems to be a bug (or maybe not) where the egg clowns still run away after placing a lamppost on them. I forget what they're called but you know what I mean haha. Thanks for the game.