Top down shooters is one of my favorite genres our there and you've absolutely nailed this game. I find the difficulty well balanced while engaging. I also dig the effort placed into making the game feel juicy. Game feel is one of those things I value in games and I am glad to say this one had done it well. I also like how the abilities for each size does have use at all times even if the enemy of that size does not show up. I especially like that the piercing rounds from the medium size and the shockwave from the large size works on all sizes allowing them to have more uses than just killing the specific enemy.
If there is a few things that I would change, it would be to make dynamite more intuitive to use as it is now hard to make it explode the exact location I needed. I would also give the 3 sizes a different colours to make them stand out.