Casual games might go along the same line too, and they tend to follow the "easy to play, difficult to master" doctrine as a "hook" for players. So it was no surprise (despite my laughter), when Cincauhangus told me that he actually sucked at Solitaire. If there's any semblance of surprise, that's because no one tells another person how bad they are at Solitaire! LOL.
Some games, like Tetris, Minesweeper and Digidrive do not have a winning condition, you just have to beat the current high score. Persistant world games such as Animal Crossing do not have a winning condition too, you just have to continue playing, collecting stuff, picking out weeds, etc, you get the drift, it's the daily grind, in virtual form!
Looking at my video games library, there are actually games with no distinct winning conditions, which has led to some of them to be called not as games. What do you actually do with Electroplankton and Jam Sessions? Well, make music. The latter even allows you to treat your DS as a guitar and the only semblance of it being a game is that it uses the Konami Code to unlock more songs.
So what video games have you played, that don't really feel like you are playing a game? Please don't answer GTA though, as it would show that you can't distinguish between video games, and reality.