World of Goo and Cave Story remain to be among the best, for those of you who haven't tried them.

I got the achievement after beating one of the cotton alley dark world levels.  It was strange to me, because I still had about 5 levels to go before completing the game itself.  Regardless, I didn't consider myself done until I had completed the last few levels of the game, so I spent the last few days chugging away at those levels.



Lo and behold, Seneca Falls was the true achievement I was proud to get in the end of it all.