During one of the storyline missions in Guild Wars 2 -- these will vary based on your answers to multiple choice questions when you make your character -- I had to investigate some strange goings on in the sewers of Lion's Arch, the game's main city..
The Errant Signal YouTube channel has an episode on gamification where he talks about achievements. To paraphrase him (with much less wit and beard), this kind of achievement, where you know the parameters beforehand (Kill X of Y) serves to disengage you from the game, where you are no longer playing the game for the sake of the game, instead the game becomes the barrier between you and your goal (X dead Y).
The other kind of the achievement occurs when you are doing a task and are rewarded when you weren't expecting it, and it also has to do with being rewarded for doing something well, not doing something a lot. The second kind is clearly harder to implement in a game. I can barely come up with any examples, and the ones I have are not 'achievements' per se: Diablo3's rewards for killing N monsters in a short time span and the flawless victory in Mortal Kombat.
Do these threshold type achievements really keep people playing the game in the long term? Or do they cause intense bursts of commitment that ultimately hasten burnt out? Tom, you were playing GW anyway that day, but instead of wandering around doing something f*n, you hit the attack key 5000 times in a dark sewer. Perhaps that increased your game fatigue to the point where you will now quit Guild Wars2 in 732 days instead of 736 days?
Excellent observations, sid. And as John hinted, I don't generally have the luxury of staying with games over the long term. Partly because of the kind of work I do -- I can't very well NOT write about Borderlands 2 next week, as much as I'd love to stick with my love affair with Guild War 2 -- and partly because I'm very much a videogame dilettante with a short attention span. That time spent killing rats should have been spent enjoying content that I would have experienced if ArenaNet hadn't dangled a rat-killing achievement in front of me.