The underlying gameplay does a pretty good job at building itself around Wall-E's primary ability - he makes cubes of trash. There are four types of trash cubes and each has its use for helping him overcome obstacles. Normal Cubes are good for activating far-off switches, while Heavy Cubes can weigh things down. Magnetized Cubes attract certain metals and Energy Cubes charge up long-dead machines and in a pinch, make a handy explosive.
Most of the game consists of large obstacle courses where Wall-E uses the different block types to solve puzzles and his limited jumping ability to navigate platforming sections. These areas are a little more complex than the block puzzles, though the path is always easy to follow.
The only time Wall-E gets interesting is during a handful of rotating stages that feature long, triangular stages that can be flipped around into different configurations. Each side has a different puzzle and if you can solve all three sides, it'll usually unlock bonus stages where Wall-E can collect treasures for his collection.
Eventually Wall-E runs into Eve, a sleek robot whose second cousin is probably an iPod. Eve's introduction also brings with it a different play style. She can fly around levels and comes armed with a laser gun that is capable of causing a good bit of damage. Even when playing as both characters, the gameplay can't escape being anything more than a mindless romp through the game's plot.
Eve's sections are split between open flight areas and tunnel areas. Open flight areas are mostly scavenger hunts where you look for plants and other objects. Like the platforming areas, the open flight areas have a linear feel that guides you through the level, removing any sort of challenge. Tunnel areas usually involve some sort of race, but are hampered by iffy controls.
Later in the game, Eve's sections turn into straight-out shooting levels, which is an odd design shift when you consider how non-violent the first part of the game is. The shooting areas are much faster-paced than other areas, but are just as mindless. Eve can automatically lock-on to enemies, so all you are really doing is pushing a button and letting the game do all of the work for you, leading to overly long, dull levels.
A few multiplayer areas are included, though they add very little to the overall game.