Use A and D or the Left and Right arrow keys to move. When you find your abilities, press Spacebar to activate ALL OF THEM. To make it through each level, you will need to switch the order that you use the abilities. Click on the icons in the bottom right to switch the order. To do one you have to do them all, so plan your moves wisely!In this article, one button is the limitation on interaction. Using this limitation, the reader can then draw their own conclusions about how these ideas may be exploited on multi-button interaction systems.Join now and have fun!