Very good entry, I do love the core idea of your game!
I'll just point out a few things, but first I must say I overall enjoyed playing the game a lot! I would have really love to have a bit more feedback (screenshaaaaaake on explosion for exemple :D ), and also I found the D20 use nice but really hard to use well.
Nonetheless, those points are minor problems, and this is definitely a pretty solid and pleasant entry, congrats to you all!