Ah, I think you have a frame-rate physics problem! My character does not jump nearly that high.
Viewing post in Big Bunny Little Bunny jam comments
Yes I can jump higher by holding space, but not that high! This bug is usually because of an effect called frame rate physics, where the physics are called every frame but the frame rate is not consistent across two different setups. If you put all the movement code in _physics_process that should fix this, alternatively you can mess around with the delta variable but it's more finnicky.
Sorry for the delay, here is a video of me doing a jump while holding space as long as I can, and as you can see, I'm not getting the jump height similar to your clip. This is on the web version of the game.
https://streamable.com/pmx9vn