Really cool and polished entry! I have a few thoughts;
Firstly the positives, really polished, nice effects and simplistic art style. Really fun to play and definitely the game i have spent the most time playing! I think the theme could of been fit a little better. I get that when you die (end as one character), you come back as another. However I think its a little less interactive and placed there just to fit the theme slightly.
I also thought the ai had way too strong aim lol. I was getting lit up constantly. But the nice controls made it a little less infuriating since there was different things I could try to get the jump on them.
Overall I think it was a really good entry and very polished and fun to play! =D