RotoCube
One of the simplest games you'll ever play, and one of the most challenging

Rated as by HOTU

Rotate and scroll cubes, columns and rows to make each cube a complete color. Every new level brings a unique challenge of increasing difficulty, as the colors get more and more mixed up for every level you clear. For every new level you are given a number of moves, and for each move you make your score decreases. - When you are out of moves, you are out of luck! 

To start with, the cubes are only scrambled by One random move, and you will find it trivial to find the solution, but the level of difficulty soon increases.

How to play

Scroll columns/rows
by clicking on the buttons on the side of the board.

Rotate cubes
by left/right clicking on them with your mouse.

Undo/Redo moves
by clicking the forward/backwards buttons, rolling your mouse wheel, or the arrow-keys on your keyboard.

Exit game
with the [Esc] button on your keyboard, or use the [Exit] button.

If you give up, you have to press the "Surrender" button, to be able to start a new game. When you do this, you will also be able to see the correct solution by using the undo/redo move commands - prepare to slap your forehead!