I absolutely love this! Thats a very unique take on a deckbuilder and its masterfully crafted! I've never played anything like it before and its so good! This has a lot of potential. Can't believe I found this last-minute, thank you for sharing it on discord.
If I had to point out something I think it could be improved is some of the SFX and graphics for the gladiators and waves. They could have more emphasis on screen, maybe rearranging the roulette and its pieces on screen to show a bigger battlefield and more detailed warriors. Also, I got a little confused at first, because normally our player is shown on the left side of the screen and the enemies are shown on the right side, so I thing switching the sides could make it more intuitive.