It's buggy, but certainly not unplayable.
Did you check the controls on the game's page? When you press shift/left click midair you ground-pound instead of switching sides and if you keep it pressed until you hit the next wall, you'll swing up and down faster because your momentum doesn't get reset.
Did you download the executable, or for some reason you could play in the browser? I don't know what the browser version looks like, so if you did, I would suggest you try playing using the executable.