I think this is the best Robot Day submission I've seen yet! Granted, it's only the second one, but it's still really cool! I think what mostly works about is how you let the game play itself. It's interesting to see what kind of things, you, the player, can put in motion. As expected, you can't completely block them off. I think it would be cool if you could do that and they could destroy the towers in their way.
The music was also great. I like how each of these monsters are designed in a different way. It's especially funny to see how they clumsily just fall onto the ground. Dang, those bosses are harder to kill than every single enemy combined on a level. Happy Robot Day!
Pretty decent tower defense game, except for the defensive wall which makes the game really easy