I know what Tamagotchi Party On is lol I never played it but I used to have a bunch of little Tamagotchi that I played with a lot. I remember I even took them to school but eventually they got banned so I couldn't do that anymore XD
I think I've seen those DS games in Gamestop before; was the game called Corner Shop or something? Lol that seems like that could end up being an addicting game somehow :P Usually the simplest games end up being the most addictive for some reason xD
Yeah, we used to play Tamagotchi Party On a few years back (It's like a poor mans Mario Party if you didn't know). Anyway, the games take about 10 hours each, and as I always played as Kuchipatchi I got kind of attached to him, the little duck-mouthed weirdo!
There was also a couple of games on the DS where you could own a bakery and dress your Tamagotchi up - had a great little pair on dungarees on him! So that game was strangely addictive, not really sure why when I read back my description of it.