I have a few critiques. For gameplay, at the moment it is kind of difficult to coordinate your troops. For instance, the most common strategy here would be to send in the big guy to take the damage from the towers and then let the little guys sneak past, but because they always walk at a fixed rate from the moment you spawn them its hard to get them to sync up.
For design I think the game needs more context, I still don't really know what the fire button did besides burn 5 of my souls.
As for something good though, the art was the best part of the game in my opinion, and I can tell that the artist put in some decent time on making it all look nice. Also, I do like the amount of levels you have and how they are structured in the level select screen it looks really good