The grey square will follow the arrow key inputs. If you hit a falling block or the edge, you die. As you dodge the black shapes, your level progress increases. Each level is different than the last. Press space to pause and unpause. Good luck!
Updates July 10, 2015 -Fixed the bug where when you finish the game you can't restart. -You can now see your level progress in the top left corner. -Added pausing. Press 'P' to pause and to unpause touch your player with the mouse and press 'P' (to prevent cheating like pausing, moving mouse and unpausing).