Great use of the theme! When I fell I couldn't access the first orb that makes the rest of the level accessible so had to refresh the browser page to restart the game and instantiate it again. I also accidentally left the bounds of the map and just kept falling until I refreshed the browser and restarted the game. I think music would make this even better (especially if it changes when the level design changes and the timer is active), but I think you've got a really cool concept on your hands!