depends on the game, achievement hunting can be a lot of fun in a game u already love its just more stuff to do and more reasons to play, sure if all the achievements in a game are things like getting all of a collectible or beating certain story missions/quests they are pretty boring but in pdx map simulators for example many of the are interesting run ideas or they indicate where the hand crafted content is at. And despite how much i love the game i dont think i would have played as much of Tyranny as i did if i hadnt decide to get all the achievements.