Playing with portals

I got onto Portal 2 pretty much as soon as it came out because, despite the godawful fanbase, I thought Portal was a really clever concept with great execution. Not a day later and I've already finished it (though I'm yet to try co-op) so I thought I'd make a few comments on it. Fair warning - I won't mention any spoilers but some details in the screenshots could give stuff away if you think about them too much. I myself was actually spoiled courtesy of /v/, but the event I was spoiled about happened about halfway into the game so it wasn't a big deal.

The game itself is mechanically pretty similar to the first Portal - you have a portal gun, which you use in combination with cubes, lasers and various other devices to make your way through each test chamber. One of the main areas in which Portal 2 differs is that it includes a lot more of these devices that you have to use successfully to continue through the game - including light bridges, tractor beams, jump plates, cubes that redirect lasers and, my favourite, three types of gel that affect the surface they're placed on.