Good online Rubik's cube games are available at Kongregate.com, MathPlayground.com and OnlineGames.net. Google also offers a simple but sleek and easily operable virtual Rubik's cube.
The "3D Rubik's Cube" game at Kongregate.com offers access to different cube sizes, thus offering multiple difficulty levels. The player can choose between the classic three-by-three cube and the more unconventional two-by-two, four-by-four and five-by-five cubes. After players choose a size, the game automatically shuffles the cube. The player can then solve the cube by dragging a row or column in the desired direction. The player can also customize the cube's colors, change the rotation speed or save the current position.
The Rubik's cube at MathPlayground.com keeps track of the moves players make and the time that elapses while they solve the puzzle. To rotate a row or column, the player must click on its corresponding arrow. Clicking and dragging the cube rotates it to expose a given side.
OnlineGames.net offers an interactive Rubik's cube as well. After pressing the Shuffle button, players can interact with the cube by clicking and dragging its rows or columns.
Google's Rubik's cube is simple, but provides a realistic playing experience. Players can manipulate the cube using the mouse or keyboard shortcuts.