If you haven't been able to play due to the screen resolution, I haven't fixed this yet but if you zoom out with the browser zoom, then back in to 100% the screen fixes itself. This is required for each level too. Working on a real fix.
additionally the controls aren't showing up for level 1 so here is the blurb that is supposed to show explaining what to do while i work on these fixes.
"Cross the log without falling off. Be careful!! Hold left and right to maintain balance. Hold up to move forward. You can either move or balance, not both." Press A to start the level.
Sorry it definitely isn't ideal atm but it is technically playable