Mouse: Draw on grid. Spacebar: Confirm selection, open pick block menu. A: Scroll left in menu, rotate some objects counterclockwise. D: Scroll right in menu, rotate some objects clockwise. C: Clear the grid. W/On-screen up button: Move up a level. S/On-screen down button: Move down a level.
Rotatable blocks are marked with green in the pick block selector. You can change the color of Solid Block to place down using the rotator keys.