WASD to move. S lets go of green later in the game. Space to swap portals. There are 2 portals: Red and Blue. Click to shoot! When it starts, it will ask if you want to load a checkpoint. Type Y to load a previously saved one, n to start from the beginning, and erase to reset data.
The main idea, as many can tell, is straight from Valve's Portal game. This is not an original make. The code was all made from scratch. No pun intended. 1.1 Did a few bug fixes and added some new levels.