When I load your game in my browser (Chrome/Windows) the end result is blurry. I don't know a lot about Unity, but I know there has to be some settings/code that could allow you to not have the pixels blurred together as other games use unity and don't have that issue.

That being said I enjoyed the game and I like having the option to undo. 

the game has improved a lot since the last version, music and sound effects are great, it would be nice to have a level indicator though 

altough the game is fun, it doesn't fit the 64x64 rule