I'm a bit of a 'completest', just hate to leave things undone, suppose it's what's now come in part to be known as obsessive compulsive disorder. While a lot of video games are 'without end' like Space Invaders, Pac Man (though that's not entirely true, seeing as it crashes at level 256), the vast majority are story led, they have an end and for someone like me that can become a bit of a problem. I recently came into possession of an xBox 360 and found the interesting "achievements" feature. Play 100 Games of Hexic and get an achievement activated, complete a level in Prey, and get an achievement.
While many of these can be a simple case of just starting the game, a number of them require some dedicated amounts of gameplay or a convoluted number of combinations of otherwise pointless actions.
As with most things these days there's a seemingly large online community of people dedicated to getting 100% of all these achievement points in each game they purchase, unfortunately I imagine there's a number of real life achievements they're possibly missing out on in their quest for online bragging rights.
So I guess my own problems with being a completest arn't that great, I still would really really love to know what happens when you finish Frankie goes to Hollywood on the Commodore 64 though…