Walk around with the arrow keys! The signs will give you most of the instructions, but just in case you miss any of them, then: Click on either player 1 or 2 to change how they look. 1- turns on 1-player mode 2- turns on 2-player mode and teleports the 2nd player to you. A,W,S,D- used to move the 2nd player. T- talk to any sprite your player is touching, including signs. M- the radio man will explain this one ;)
This is probably one of the first add yourself projects that can potentially be infinite. Most add yourself projects are limited to the space of the screen, but not mine. If you have any comments, suggestions, or insults for me, then go ahead, give 'em here. In the future, I might make a sprite of some sort that you can look inside it and it will give you instructions on how to make a house/sprites of your own on this.