Portal 2 is everything you want it to be and a little bit more. Which, actually, is probably exactly what you want it to be. Yes, it will warp your understanding of how space and geometry works, but it will make you giggle while that happens.
If you're one of the two people I need to explain Portal 2 to: it's the follow-up to Valve's 2007 physics-based puzzler that was named, 100% appropriately, Portal. In both games, you're Chell, a test subject made to jump through an increasingly brain-scrambling array of hoops that also double up as holes in the fabric of space. Testing out a portal gun under the watchful (and double-demonic) eye of AI GLaDOS, you have to navigate various hazards and obstacles to get through test chambers and stay alive.
Completing the puzzles demands the creative use of the portals and the sometimes freaky effects they create. For example, a prominent feature of the first game were the puzzles that required you to jump from a great height to acquire momentum that would then fling you out on a horizontal axis over a gap blocking your way. See?
No? Here, have a look at this video showing off the fancy boots that stop you breaking your legs. It gives an idea of how the portals work:
We all up to speed? Good. So, I'm going to say it now: Portal 2 is brilliant. It takes the beautiful, ingenious design of the first title and builds a big, fat rewarding game on top of it. No-one came in and went, "Hey, what if the portal gun was a machine gun?!", no-one tried to reinvent the wheel ? Valve simply picked up the cube and ran with it.
The developer has added length, scope and new gameplay features to create something that will stretch your brain in awkward directions in the best possible way.
I'm not going to go too deeply into the added gameplay elements embedded in the environment since that feels like spoilers for a game like this. But you've seen the likes of the repulsion gel, which acts like a spring pad on any surface it coats; and you've seen laser redirection cubes in videos. The new additions provide plenty of added depth to keep things interesting as you progress. There was not one point in Portal 2 where I really felt like I was retreading ground.
This is helped by the fact that more of the action takes place beyond the bounds of the test chambers. A disaster has wrecked Aperture Laboratories and it provides ample opportunity to explore beyond the confines of the roughly reassembled testing rooms. It also impresses a scale on the player that wasn't in the first game. The action of Portal could have taken place in a reasonably-sized out of town industrial complex, but in Portal 2 Aperture feels vast. It feels like you could be on the Death Star.
This sense of decayed grandeur is an important part of the design. Eight to 10 hours of test lab after test lab would, let's face it, start to wear on your eyeballs. The austere environments of the test rooms fits well with the overall feel of the game, but it doesn't offer a vast amount of variety. With the additional run-down scenes of devastation, that bullet is dodged.