Simply incredible. I love it.
It was pretty easy once I got the dummy on hp loss. Later I could heal on swap, then switched to teleport on swap. Eventually I got to spawn mobs on ally death. Ha! I once got cornered by my own spawn as I was close to reaching the next level.
Anyway, I believe this game could be huge or am I too optimistic? It's already addicting as someone else put it in the comments. I think your game would be even greater if you added more interactions with the environment, new environmental elements or different worlds like lava, many more levels (and perhaps different difficulties), and a limit on the DNA sequence (or not)!