This post is from the now defunct website “A GameDev Plays…”, copied here for posterity
The original Portal was a FPS puzzler of near perfection, can lighting strike twice with its sequel When using portals, definitely!
Playing this is as close to gaming perfection I have ever managed. I found myself getting lost occasionally in the middle transitional levels - that is the only negative thing to say about Portal 2 - everything else is praise. The FPS gameplay is super smooth. The puzzles are just right. They take a little thought and make the player feel like a genius once solved, but never get so hard as to cause frustration and rage-quitting. There are lots of little extras and hidden features. The story is entertaining. Glados is one of the best computer game villains ever. The new character Wheatley is good too. It is actually a funny game - a rare achievement. Seriously, if you haven’t played this, you should. Don’t just take my word for it. According to Steam it has a 98% approval rating and completion rate of 37% - a huge number (it is normally under 10, my game has a completion rate of <1). Highly recommended.
Portal 2 is out on the Steam store for PC, Mac and Linux at US$19.99.