Metroidvania-style games are always really tricky to execute within such a short amount of time, but you seem to have done a really good job! The movement is surprisingly nice to execute, and the difficulty of the obstacles seems to ramp up with how far I can get through the dungeon, which is quite nice.
I have 2 little nitpicks that I think would go a long way:
- Have a timer on screen to show the countdown from the poison. When I was dying felt a lot like guesswork and there were times where it really felt unfair. It would also help solidify the jam theme for the game (not that the theme isn't there, it would just make it more present)
- Making the dungeon smaller wouldn't hurt. I don't know if I was missing something, but the runback to the far east room was super long, and it felt like because of that I only had one attempt on that room that was already pretty challenging.
Those were small nitpicks though, and overall the game is really fun. Great job :D