You're right. The mouse escapes the game in the web version. We didn't notice this since the problem doesn't exist in the windows build. I wish we had the time to implement controller controls for the light since the character controls are already fully functional with a controller and I believe that it could feel more natural with an analogue stick. Oh well...
I also agree that we should have pushed the puzzle aspect a bit more rather than making many dexterity challenges. Personally I'm a little tired of box pushing puzzles but observation and navigation alone can provide some interesting challenges with this shading style.
We simply ended up running out of time and built ten levels within a few hours without the time to think about too many clever puzzle based challenges.
I'm glad that you still liked it and I thank you for your detailed feedback :)