I find them relatively inoffensive, though there are some that are just dumb, such as those unlocked through natural progression be it story or kills/kills with certain weapons/tactics are a waste of time. Then there are some that challenge you to approach a game in ways you wouldn't have even thought about, which are becoming more and more rare these days.
A good example is my favorite achievement of all time, 'Little Rocket Man', in hl2 episode 2 where you have to take a garden gnome from the very beginning of the game and carry it with you all the way to the end and throw it into a rocket. And it's not like the gnome just sat in your inventory, you have to hold it with the gravity gun, which is the primary weapon in episode 2; frankly, at times it was a hassle and annoying, but when I got to the end and threw that lilfuck in the rocket and saw it take off it gave me the weirdest sense of accomplishment like I had never felt before when playing a game.







