This is a great idea! Unfortunately I did find it really buggy (not clear when dice are supposed to roll, sometimes they roll when placed into the squares and sometimes they just roll and then don't seem to count, you could counter this by having the dice pop back to the start after being used and maybe a column for rolling before you place them into the slots for move and shoot).
However, I can see where you were going with the game, and its a great idea! The art is really well made, and look at that tiny file size, I haven't seen that engine before, but its impressive you crammed all that into the game! I hope you keep working on it after the Jam.