Congrats! I thought the ending was a little weak too - I was geared up for the mother of all battles, and then....
I finished Quantum Conundrum
, a Portal-like puzzle game where you progress through a series of puzzles connected by corridors. The gimmick is that as well as being a puzzle game, it's a platformer, and sometimes a quite hard one.
You have access (eventually) to four powers - reverse gravity, make everything feather-light, slow down time, and make everything iron-heavy. These combine into a series of sometimes-fiendish puzzles, and lots of madcap platforming - for example you can make a safe light, throw that safe in the air, slow down time, clamber aboard the safe, unpause time and sail over a bunch of obstacles unharmed. Ingenious really. Some of the platforming is inspired, some is annoying (all done in first-person too).
I started off not liking it at all but it really grew on me as I progressed.