Instead of the animation speed setting it should have a slider (like, for instance, here http://debug.elm-lang.org/edit/Mario.elm http://debug.elm-lang.org/edit

Instead of the animation speed setting it should have a slider (like, for instance, here http://debug.elm-lang.org/edit/Mario.elm http://debug.elm-lang.org/edit/Mario.elm). Otherwise, it's more like a nice animation than a learning tool.