I'm sure you have all played some games that started out pretty good, but then began trailing off and either became repetitive, or boring. Feel free to name some of those games in this topic.
The main game that made me think of this topic is Katamari Damacy. I really had a blast with Katamari Damacy at first, but after playing the game for a few hours, most of the levels started to feel the same, and even though it was upping the ante for every new level, it just starts to get boring.
I never played any of the other Katamari games. The first one was more than enough for me. Great music though..