i think i might be ableto answer ur question, my cousins are in that category, they always come over to play on ps3 and i try to accomodate them by putting a game that they might like, i found that not even games like arkham city are interesting to an 8 yr old,they dont understand, littlebigplanet is alright, but not that great
littlebigplanet karting was something they were really into, ps they have tried every game i have had, COD,battlefield, prob shouldnt have let them play last of us...they didnt get past the 3 part haha
racing games always work, but lbp karting is super simple, also nba 2k12 was a hit...who knew, but they hated fifa 13, not that many games for them, i would also try the indie games, labyrinth legends was a good one