First, how to install:
Was with me on my Intel i7 PC with 64-bit Windows 7 and 6 GB of RAM no problem. Of course you have, as some reviewers have noted correctly, wait for Steam to update download, which requires a lot of bandwidth because he felt astronomical shoveling a lot of data over the wire. But if this is done once, then everything works fine. Crashes I've had to date, no.
Then the game itself:
Compared to portal 1, the second part of a much more beautiful in many areas and detailverliebtere graphics on, here the creators have really invested a lot of work that can be seen clearly. There is also a whole range of new, partly designed puzzles, additional gimmicks and huge level. That's the first place, fine, I found the first part but in parts too light and too trivial. Unfortunately, there is between the individual test chambers partly seemingly endless animation and explanatory sequences in which eg. The Roborter "Wheatley" which accompanies a at a certain point and shows up every now and then, downright zutextet. It starts to tire quickly. Also, some routes are simply too long. So you do not consume a lot of time about playing or when solving puzzles but in these "filler sequences". Also, the degree of difficulty between the individual chambers varies greatly, and it really just "very difficult" and "very easy" are here. Some puzzles can even solve a toddler, you're finally ready in just over 1 to 2 minutes, in other areas it requires quite a corresponding amount of brain power, a lot of time and tact to get the solution even begin to track. A slightly larger variance and a slow increase of the difficulty would have been in my opinion much better and more exciting.
The bottom line, therefore, Portal 2 also affects me as an extremely high gepushte version of the first part, in which the creators did not put much more emphasis on the visual appearance as the pure puzzle and game. The game is certainly worth no flop, and his money, but it does unfortunately much half-baked as the first part.
Hence the conclusion: 3 stars for the game, 4 stars for the game as a whole.