This is very fun to play and I love that the characters are so full of personality! Nice concept.
The things I enjoyed the most were: the fact that the potions had different effects, the music matching the whole mood of the game, and the whole survival/arcade-y aspect of the game.
For some reason, the game lagged when I set to fullscreen so I went back to windowed and all was good. One suggestion I could give is that I think the potion refill item should spawn more frequently (I died on endless mode because I couldn't find any more potions). And maybe, instead of having a "hard mode" already checked at the beginning, there could be a "casual mode" (to show that the "hard" mode is the way the game was meant to be played but if that's too difficult you can change it to casual and enjoy the experience - like some roguelites do). To be honest, I'm saying this but I'm not sure what is the better option haha.
Anyway I had a great time playing this, it's super fun. I liked kiting enemies into the pools and running around. Great job!