A/D or left/right arrow to walk

right mouse button, X or up arrow to jump

S or down arrow to crouch

while crouching press S or down arrow to fall off cars, scaffoldings or ledges

stand before the blue marked canvases and press space

now you can choose between the graffiti pieces by pressing A/D, left/right arrow, Q/E or Z/C

press space again to choose the piece or press right mouse button or X to abort

stand before the piece and hold space to paint until the piece is finished

You can also choose between pieces while waiting or walking by pressing Q/E or Z/C.

This is useful since it saves time.

The game saves automatically every time you enter the map.

Check out the tutorial level for further instructions.