Likely to be the highlight for kids are the competitive multiplayer attractions of Mario Chase, Animal Crossing: Sweet Day and Luigi's Ghost Mansion. The easiest games in the pack to get your head round, these are basically variations on the playground games of tag and hide and seek – Mario Chase sees a group of Toad characters scouring a map in search of the red-hatted mascot, while Animal Crossing: Sweet Day has a few comically large-bonced animals racing round picking up as many sweets as they can whilst avoiding capture by GamePad player's guards. Luigi's Ghost Mansion has the GamePad player taking on the role of a ghost invisible on the TV screen who needs to catch a group of ghost hunters, who'll be trying their best to catch him in their torch beams. For a co-operative game, Pikmin Adventure is likely to be the best bet, as it's a simpler smash 'n' bash romp through a world inhabited by oversized space creatures intent on having you for breakfast. It's worth bearing in mind, though, that the three competitive multiplayer games don't have a single player mode, so you'll need at least two players (and preferably four) with the relevant peripherals (most competitive games can be played using just a Wii Remote, whilst most co-operative ones require a nunchuck and a Motion Plus add-on) to get the most out of it.
Conversely, the games that may pose more of a problem are likely to be The Legend of Zelda: Battle Quest, Metroid Blast and Takamaru's Ninja Castle. These seem to be the games aimed more at the 'serious' player, and as such have a bit more of a learning curve, or tend to be generally more difficult. In Zelda, the player with the GamePad acts as an archer to the Wii Remote player's swordsmen, as they fight their way through a series of felted enemies in pursuit of the legendary Triforce, but with health shared between all the players (meaning a lone not-very-good player is enough to halt the entire team's progress), some devious enemies and a tendency to leave the GamePad player behind, it's probably a bit on the tricky side. Even more problematic, space shooter Metroid Blast's ship is steered by a combination of two analogue sticks and tilting the GamePad, which is an awful lot to think about even for experienced players. The other players don't have it much easier either, moving their players with the Nunchuck and aiming with the Wii Remote's pointer. And while Takamaru's Ninja Castle's 'point controller at the screen, swipe Touch Screen to shoot stars' concept is a lot easier to follow, in practice it's nigh on impossible to hit the majority of the speedy Ninjas with your shuriken as the game takes into account both the direction you're pointing the controller, and the force you put behind each star, meaning you have to get two things right.
That said, with the right group of people, your child will likely get hours of fun out of Mario Chase, and the other competitive multiplayer games, which truly show Nintendo at their same-console multiplayer best. Like most minigame collections, it's one of those games where kids will likely find a game they like, and then play it over and over, ad infinitum, until you need the TV, or tell them it's time for bed.