The first screen is sort of a tutorial, though. If you go right first because you've played Super Mario Bros. or some other platformer and you think going right might be the way to win, you're presented with a narrow passage you can't crawl through. At this point, you'll discover that you can also go left. There's another rock formation with a narrow passage, but from this side you can jump on top of it to get over it, and you'll find the Morph Ball. From the Morph Ball side, you can't jump back over, so you have to figure out how to get through the narrow passage by pressing down to enter Morph Ball mode. Now you understand the game: find obstacles, acquire the corresponding upgrades, use them to bypass the obstacles.