Took me waaay too long to figure out I could double-jump and then similarly with activating the vampirism. Eventually I read the page and figured it out. Would be nice to have more in-game hints for that sort of thing though.
I was also surprised that (at least on Linux) pressing escape quit the game, which was a bit frustrating because it meant I lost my progress. I kind of wish it wasn’t timed, or at least that the time left was more obvious.
Regardless, I liked the idea of the drinks unlocking additional vampiric powers, and as a result getting stronger as you go. Nice work!