Use the arrow keys to move Jumpman left and right, and make him jump. if he touches the side of a platform, Jumpman will automatically climb to the top of it. Also, if Jumpman falls off of a platform, he can get a magic Midair Boost by pressing the up arrow. Basically he jumps in midair. This makes it easier to progress through the thirty levels that make up this game.
If you find any problems let me know.