When I open the game in Chrome the frame is relatively nicely sized but the game itself is literally 64x64 (not stretched) making it hard to see anything. Perhaps something with Unity WebGL export settings?
I resized the canvas to 256x256 using the Chrome Web Inspector and it was playable. I got stuck few minutes later because I blocked my path with some falling gravel. I like the idea though. Nice visuals and I'm a sucker for puzzle games.