That looks like a really good Achievement breakdown
Difficult enough to make the achievement's worth while but not stupid difficult like "become the best player in the world"
As for the game being in development for 10 years... they STARTED 11 years ago, worked on it for a while then the project was canceled... after a while they picked it back up and re-started from scratch.
It was started in '95 and then canceled in '99 due to major engine problems. Rumors started floating around '02 that the game had been picked back up and it wasn't made official until last year.
They trashed their original engine in place for a heavily modified version of the Doom 3 engine but the story and general game design remained the same as what they'd had back in '99