Hi! one of the devs here (art and design). Thank you so much for your feedback! I'm glad you enjoyed the game so much :0
Some of the flaws you listed will hopefully be fixed in a post-jam version. We've received a lot of feedback about the controls, so we'll likely add alternate bindings in a short update once the jam is over. We'll also probably try and update the speedrun controls as well as the disappearing potion bug.
As for the potion jump, being able to throw it downwards / diagonal jump was an intentional feature. (Being able to throw the potion directly downwards was an addition later in development after players had difficulty landing the potion jump) However, the levels were designed without it in mind, since most players weren't able to consistently pull it off, hence why it feels like an unintentional addition.
I'm super impressed by your speed run! One of the first ideas during development was to give the player a high skill ceiling in regards to techs/movement abilities, so it's very satisfying to see somebody put that to the test. Especially seeing how quick you beat the boss, lol.
We hope to see you back for the post-jam build! :)