Thanks for your comment ! If its because you can't jump high enough, its because I used delta time so according to the frame rate, the jump height changes...
Yes, I think so too but I didn't know how to do it...
You use Love2d right? You could take a look at this then: https://schellingb.github.io/LoveWebBuilder/package
It didn't works for me for the first couple of times, but now I always use this in every jams I participate. It really nice since people can access your game more easily.