So I saw this game on the front page of speedrun.com, and decided to try the flash version. I was trying to figure out optimal jump timing, but while mashing jump I got a REALLY high jump compared to usual. I was playing in level 3, and jumping from spawn I managed to go so high everything but my foot was off-screen.
It's fairly inconsistent though.
https://imgur.com/Sttv7iZ

Edit: this is how early I could do level 3, managing to jump right over the spikes: https://imgur.com/W5PkATm

Yep, it's called "Super-Jumping" by the developer. It's a known glitch that occurs when you double-tap the jump button very quickly. It allows you to do crazy shortcuts but sometimes it messes up precise jumps. Even if it is pretty fun, the glitch is fixed in the full version of the game.

Okay, thanks