In order to kick the wall you will need to press the Ctrl key and to move the character into the wall using the arrows. Once the hero is touching the wall, press and hold again the Ctrl key. Sonic will move slowly to the ground and you will need again to press Ctrl. It will automatically jump into the next wall. Once it touches it, quickly press and hold Ctrl. Do this until Sonic reaches the end of the walls. Use Google search engine to find walkthroughs and tips. The first link, is a video tutorial with the entire first level.