Not too bad for your first jam!
The idea was interesting although I see a major problem, which is also the reason I wouldn't be playing this game for more than 10 minutes. There is no way to loose! There are no high scores. I can take as much time and re rolls as I please and I won't be punished in any way. The enemy simply waits for their inevitable demise. I wish for more of a challenge.
I read that you only used 8 hours. Why is that? Your game could use an hour or two of investment for some music/sfx and some rudimentary loose condition.
Tutorial was nice and the assets where implemented well. Overall decent entry.