I had a lot of fun with this. The devouring animation felt really satisfying, especially with the particles coming off after eating the orbs. I also thought the floatier movement and dash worked really well together. It made kiting enemies feel good without feeling too stiff, and the fights were fun in general. The enemies fleeing once they got shrunk was such a good touch too. That made the shrink theme feel more alive.
I liked the sense of progression as well, especially getting attack speed upgrades throughout the rooms. Also, nice call with the respawn points; they really let me relax and enjoy the game. The sound design was well done. The impacts had a gentle but gross wet noise, and the music/ambience really set the atmosphere. The heartbeat sound when low health was also nice, along with the creature flashing.
Nice work. I'd definitely be interested to see where it goes if you do end up expanding it into a bigger roguelike later.