Bearing in mind the enemy attack bug, I thought this was a neat concept! Spinning Slay the Spire into a Hololive theme has lots of room for funny quirks, cards, and other sly references. The core gameplay flow from a user perspective felt pretty straightforward, though it would be nice to see that encompassed in a tutorial battle so it's more intuitive to follow and "commit to memory" per se!
I wish there was some kind of music for me to jam out to as I walk around and slap bad takos for violating the 4th Wah, but I liked the pixelated art base that you had. The swirling transition shader is a neat touch (though I'd recommend delaying the overlaid UI display until after the transition completes with an event -- or have the post-processing apply to that as well), and I think you should otherwise flesh the concept out more! Get it so you have playable runs, even if it's just one character and a couple of enemies to start. Slap some more UI in there, maybe some save state. This could be dope!