Yeah, in addition to holding 'shift' to run (in case you aren't doing it), you shouldn't just be holding space. Jump timeout is less than jump duration to give the player more control, so the idea is to press it, and then press it again after flying some time, optimizing your trajectory. Try doing it 1)in the upper point of your jump trajectory 2)in the part of the trajectory where you reach the elevation level from which you started to jump. Both these options should work fine, I left a good margin for that distance to not really require any hardcore skills. If you just hold it, it spends jump attempts on prolonging the initial jump when it's somewhere in it's middle, which is not optimal. Btw in fact quadruple jump is also supported, since sometimes you just want a little bit extra (and the player can loose one jump if ground detection isn't working at the moment of first jump, like if you start jumping too late after already starting to fall in the abyss or if the ground isn't level enough). Do you think that I should add some kind of hint to the game to make it more clear?