“I am a die-hard believer that if you finish a single-player game on Xbox 360, on normal settings, you should get something like 600 achievement points,” he said. “It irritates me to death when I get 120 points after finishing a 20-hour game on normal because I didn’t headshot 250 people through the eye.” [gamasutra.com]
I have had a few different conversations about this. I tend to agree that a number of achievements should come about as you progress through the game – and many developers agree. But I’ve also heard the argument that achievements imply a heroic accomplishment and most of them should be more rare to come by – and there are a lot of developers who follow that strategy as well. GTA IV, I think, is a decet example of the latter. Fable 2 is a good example of the former.
PS The linked article talks about more than just achievements. It’s a good read.