Nintendo’s Kirby is just a pink sphere with feet, arms, eyes and a mouth. He doesn’t appear to pose much of a threat — instead, he looks like a wad of bubble gum that, at worst, you might have to peel off the sole of your shoe.

And yet, he’s so flexible that his creators, Tokyo’s HAL Laboratory, can endow him with any skills they like. Usually, he inhales enemies to gain their powers, but he’s also starred in puzzle games, fighting games and pinball games. In the 22 years since he debuted, the Kirby franchise has become a sort of lab where Nintendo and HAL can experiment with some of their wackier ideas.

“Kirby and the Rainbow Curse” ($39.99) applies one of their weirder concepts to the Wii U. You don’t control Kirby directly; he rolls along pretty much under his own momentum. Meanwhile, you use the GamePad and its stylus to draw rainbow-colored ropes through the game’s perilous levels. The mission is to guide Kirby through the landscape so that he avoids obstacles and collects stars, food and other prizes.

Each of the game’s seven worlds offers fresh variations on that technique. Some episodes find Kirby floating through the clouds, so you need to draw paths that lead him higher and prevent him from plummeting to the ground. When the buoyant creature is underwater, you can make him dive deeper by drawing ropes over him. Some areas are blocked by clay walls that you need to scratch away before Kirby can roll through.

Kirby’s shape-shifting abilities occasionally come into play, turning the little cream puff into a powerful tank, submarine or rocket that can blast through obstacles. And each world ends with a boss fight in which you need to guide Kirby to a monster’s vulnerable spots, then tap Kirby with your stylus so he delivers a more potent kick.

“Rainbow Curse” is somewhat of a sequel to 2005’s “Kirby: Canvas Curse,” which brought a similar line-drawing mechanic to the Nintendo’s portable, dual-screen DS. The new game doesn’t require two screens; if you’re playing solo, you don’t even need to turn on your TV, since all the action takes place on the GamePad. If you want to invite friends, they can play secondary characters on the TV while you nudge Kirby along.

Nintendo’s new amiibo figurines have a limited role. By tapping one of three Kirby-related toys on the GamePad, you can boost his speed or give him more health bars. But these are minor enhancements, and non-collectors won’t miss anything.

“Rainbow Curse” looks gorgeous, building vibrant, colorful worlds. It’s easy for younger players to cruise through, but experts will find plenty of challenge looking for all the treasures hidden throughout. It oozes that special Nintendo magic that urges you to finish each level just so you can find out what surprises are around the corner.