Wicked fun and a great concept! Here is one minor suggestion after playing for over an hour:
I would say that more than half the time that I died, it was because a past me walked into me unexpectedly. I'm guessing that the death-touch was added to prevent janky strategies, but there must be a better way. It always felt anti-climatic when I was in the middle of dodging bullets.
Anyway, I'll be right on it if this game gets a full release.