Hi ryancross!
This is a really cool concept! I love how confident I was with spamming arrows, only to flop over to the lumbering beast that could barely move. In order to win, I had to pay more attention to timing and wait a bit so I could get my arrow slinging boi for the big monsters.
I think sound effects would really make this game pop. Maybe a countdown timer for when the player is about to switch so you can retreat (or advance), or a tormented scream when your poor little archer mutates into the green abomination. I think both of these would really add to player feedback and therefore gameplay.
Great start! I am happy to play it. Good luck!
Best,
Brandon from TheIndieDream