I enjoyed this one a good bit. I was quite sure to expect when i started, often slingshot games are hit or miss (if you will forgive the pun). However, upon playing i think this one has real potential. With all that said, here is my review.
Presentation:
Presentation wise the game looks simple and nice, but most importantly it is easy to read the situations, the bad guys are always clear, and it is always clear how far the player has pulled back the launcher. Having the ammo slots at the bottom was also a very nice way of telling the player what they had coming up, and allowed them to plan accordingly so really good work. Additional praise should be given to the sound effects for being clear and adding the much needed impacts and oomph that games like this need. I do not really have much in the name of feedback on your presentation, maybe add a slingshot animation after the jam, but really good work on this game, and perhaps add a trajectory line so we have an idea of where or bullets are going.
Gameplay:
As far as sling shot games go, I am no expert, but I have played a few. I have to say upfront that i really liked your implementation of the jam theme. I think it was a really good idea to have the player adjust their usage of the ammo types, and I like that the player just chose the base type and at game time the random rolls decided the rest. The act of launching the dice felt good but it would have been better with a trajectory line included in the game. I think each of the dice types served a valid purpose and served that purpose well. There wasn't one where I felt I had a useless die. I was also happily surprised with the variety of enemy types. My only feedback from a gameplay perspective is that during a wave it takes a bit too long to reroll the dice when the player has run out.
Overall great work, I hope my feedback is helpful and that it comes across that I enjoyed your game. Good luck and thank you for sharing.