Interesting concept, didn’t see that many tower defense games based on character upgrade instead of building towers since Warcraft 3 maps.
Game needs a lot of polishing. I got 2 game-breaking bugs: Credits cover X button, so you cant go back to menu. And when opened upgrade table, didnt find way to close it, so just walked away. Update window closed, but i was no longer able to open it back.
But, in my book unpolished idea is better then polished bland game.