Although I love how they threw in two level-specific achievements for each one of them, it wouldn't have taken a genius to balance them out a little more. It's particularly annoying that arguably the four hardest/most frustrating achievements on the entire list are spread among The Library and Two Betrayals, which on top of that are consecutive levels.
Something definitely went wrong with Keyes, as there is no logic in Popcorn.gif being the pick for 25G and Tying Up Loose Ends being the 'easier' challenge for 10G, as their values would suggest. While things like Wraith Hunter, I'll Be Taking That! and This One's for Jenkins! have no trouble confirming success as soon as you've met the requirements, some idiot decided to make an exception for the hardest one. It would be so much more satisfying, not to mention saving a lot of people a lot of frustration, to take out that last elite and actually knowing that you succeeded. Replaying the entire level and possibly failing again, now that's fun. Aside from those complaints though, the list is great altogether.