Many games like Animal Crossing have features that are unintentionally theraputic. The pokemon series is similar, with you going on an adventure with the pokemon you catch, traveling at your own pace, and even being able to bond with your pokemon in the newer games through the pokemon amie. I've always been helplessly addicted to tamagotchis, too; I loved that I could take care of them in real time and they could grow into different adolescents and adults depending on how you cared for them...and you could feed them, play with them...if you had more than one, they could play together or have babies...sometimes I curse Japan for coming up with the most addicting games.