I initially had the same problem, but it seems to just be a bug with the web build. After downloading, I was able to play the game just fine! The concept being able to set my own keybinds and platform placements to get to the end was pretty neat. However I do feel most people will just set it to wasd and space and get on with it, so maybe find a way to encourage players to switch up buttons. The physics were also pretty wacky, making small jumps very hard, and I was able to jump to the end platform from the start, so maybe try adding some air control.