This was pretty cool! I enjoyed the idea of just playing around and go for the strategy of your choice with only the 5 dice as resources, along with the abilities earned through enemy loot. I liked the concept of the rat fighting trash monsters, and the artwork was nice and vibrant.
My only nitpick is that it had me fidgetting for a while before I properly understood a few things, for example it's great that it allows you to re-roll, but it doesn't explicitly tells you that the dice you 'Remove' will actually be re-rolled, so at first I thought 'Why would I remove dice?, is there a good reason to play with fewer of them'? After you do it once it becomes clear but I wish it would have been more explicit about it.
Also at first I wasn't sure how to attack the defense core, took me a while to realize trips meant 'triples', for a while I tried using 3 or 6 but eventually figured it out.
That said, awesome work!