Hey. The idea of re-rolling is quite neat, as I can get better numbers as the game goes on.
The re-rolling mechanic was quite buggy tho. My dice where sometimes "stolen" by the bag for some reason and then I would not be able to place anything where they previously were.
The poker chips are also waaaaaaay to fast. So fast, in fact that the bullets would sometimes miss them. This made the first wave the first time I played feel super unfair as it has a ton of chips and I just did not have enough die to kill them.
Lastly, I wish I'd be able to see my score after losing and maybe having a high score feature too. Since you are using Unity, check out PlayerPrefs.