(Non-english native here, sorry for any mistakes/mispelling)
First, I LOVE this game. And I really enjoy speedrunning it (for the moment I only achieved times on grass & water, which are easily improvable, and I'm training Fire, which is really difficult to speedrun).
But I face a dilemma : I have found a glitch/exploit that allows the character to double jump under certain conditions. Nothing really broken : it can't be done everywhere and it is REALLY difficult to do, but it allows some time saves in some rooms (that's what makes Fire so hard to speedrun in fact ^^'). I don't know if you are aware of that glitch, and I'm a bit scared to tell you more about it because I don't know if you are the kind of developper that patch unintended (but deep) gameplay. This exploit really brings the speedrun to a new level and require very good execution to accomplish, making the run very interesting in terms of risk/reward, and it would demotivate me to run if it disappears.
That said, I didn't spend so much time on a flash game since a looooot of time, and it is a real pleasure to play it again and again. Thank you for that game !