Cool parkour game.
But the starting curve is too steep. Putting all of your game functions introduction at the first 2 level of the game is just, bad. I think it would be better to add a few more levels after the introduction of lava and spikes. I am also already stuck at the 3rd level.
Also if you can add text at the background why not add the controls as well? I have no idea jumping is up arrow instead of space.
Anyway keep up the effort :D