A very solid prototype, definitely worth expanding on. I thought a few levels had challenging solutions, but once i figured them out it was a game of clicking the right pixel. I say show the would be path before I have to commit to it so that the entire challenge is about discovering the solution rather than executing it correctly. I must've hit the reset button 100 times, it was pretty frustrating. If you don't agree, at least put an undo button.
Mobile worked pretty well, overall. only complaint is that resetting the game leaves the Haxe/source part up until you click to the right of it. making your first move difficult.
Lastly, I didn't hear any music, and you should just set RYB by default with the ability to change in the settings. Everyone knows RYB.
Keep at it!