You have a very interesting idea!
I really enjoyed collecting these combinations. It would be cool if the game itself displayed what combination the player collected.
You might not have had time to make the sounds, but for shmup you could make some visual indicators of where the boss is coming from.
Also, at first, it's not very obvious that the dice flying out in random directions are added to the player themselves (as far as I understand it myself).
It would be cool if they stopped somewhere in the middle of the screen, and the player would already decide which dice to toss out and which to take.
Also a question. I haven't been able to collect this way, but do you have any combinations that aren't mutually exclusive. How would it work? For example, you could collect all values in ascending order and so that all values are even or odd. There should only be one weapon that applies. Or both at once?
Cool name of the game, by the way. When I opened your game page, I screamed the name. Too epic to pronounce boring :D