I had to check this out due to the title and the art. I won’t sugar coat it, the art is pretty meh. The individual pixel art looks okay, but the styles are all mismatched. I still give bonus points for making it somewhat fun with the enemies rolling around stuff though, it has some charm.
Audio was okay, the I liked the sounds personally, but I can see people feeling like they are too strong.
The balance of the game is a bit off. You can just spam money makers and then you will have enough to to spam the other units and win any stages pretty easily. Maybe it’s because the units are too slow? So they give you a lot of time to prepare. You could try increasing their movement speed and see how it feels.
Overal, I think your mechanics are your strongest points. And you executed pretty well on the concept.