Resher: Game length achievements regardless of the game just don't make much sense. Many games cannot even be finished after 10 moves (not taking resignments or draw offers into account), while for others it's impossible or unlikely to go beyond 10 moves.

For instance, having to take 10 guesses in Logic is a disgrace, but you won't be able to win a Halma 10x10 game in less than 10 moves.

But even if you make different game length achievements for different games, what to do with resignments? Surely, you don't want to give an achievement just for someone resigning early in the game; OTOH, you don't want people to get pissed at you for resigning a lost game (and they feeling bad for not getting some kind of achievement).