In Happy Spaceballs you'll be picking up popcorn to increase your energy while running across the screen, dodging aliens and enemy space chips. Once you hit the "end zone", you'll press the space bar and get to the next level. You can't jump into the end zone (which is just a ring that hovers above the ground) until you've collected all the popcorn and the game tells you to. You can use the space bar to jump as well, which will help you avoid the enemies better as the levels get harder and the aliens move faster. Have a ball playing Happy Spaceballs!