Honestly, I thought it was pretty good. For only 400 Microsoft Points you get a good variety of fun challenges that test your ability in combat, stealth, and puzzles. The atmosphere of each challenge is also aesthetically pleasing and you could tell they put a lot of work into it.
However, the achievements are arduous and require lots and lots of dedication, skill, and luck.
163/164 games completed (including DLC)
Completion percentage: 100%
Latest retail completion: Dragon Age II
Latest arcade completion: Dust: An Elysian Tail
Currently Ranked #1 on Achievement Completion Percentage Leaderboard on TA