Kirby: Planet Robobot is a 2.5D sidescrolling platform game starring Kirby for the Nintendo 3DS. In the game, a force known as the Haltmann Works Company invades and conquers Popstar, turning it into a mechanical world, and it is up the Kirby to travel across the world and defeat the invaders.
The game uses a similar structure to Kirby's Return to Dream Land and Kirby: Triple Deluxe, most notably the latter as the game re-uses the mechanic of traveling between and interacting with the foreground and background. Kirby also retains his ability to inhale objects and enemies and copy their powers, allowing him to use a variety of different moves. The main gimmick of Kirby: Planet Robobot, however, revolves around the titular Robobot Armor, a powerful mecha that Kirby can control to defeat enemies and destroy larger obstacles. The Robobot is also able scan enemies and gain Copy Abilities from them, giving it different moves and attacks depending on its ability.
Like Kirby: Triple Deluxe, Kirby: Planet Robobot is a level-based game, in which players travel from stage to stage and eventually battling a boss before progressing to the next world. In order to battle the boss of each world, the player must have obtained a certain number of Code Cubes by that point in the game. Each stage contains three Code Cubes, and collecting all of them in a world unlocks a special "EX" stage. Also hidden in each stage are Stickers, collectible pieces of artwork (many of which being from previous Kirby games) that can be used to decorate the Robobot.