Colorful Cubes

Colorful Cubes is one of the Puzzle games here that asks for no download and no sign-up. It is built for touch, so a phone or a tablet is the natural place for it. Listed under 1 player, best, color, fun, html5.

It is drawn for a tall screen, so it fills a phone held upright rather than a wide monitor. Close the tab and come back later; the game is still one click away.