Use the left/right arrow keys on the keyboard to move Piggy. Use the space key to make him jump.
Move Piggy over an object to pick it up. After you pick up the marshmallows, you can throw them using the Ctrl key on the keyboard.
Throw marshmallows at the slime aliens or jump on them to get points, but don't let them touch you for too long, or you'll lose health points. Pick up food items, other than marshmallows, for extra health points.
Pick up notes for points.
Don't forget to pick up the musical instruments. That is the point of the game!