I highly recommend playing the original Portal before playing Portal 2. The storyline carries over and is quite entertaining. New ways to move from point A to point B have been added and makes the game even more fun. Included to help you solve some of the puzzles are, speed, bouncing, and portal gels that you place on floors and walls to run fast, bounce high, or open portals on floors and walls which you normally aren't allowed to place portals on. There are also bridges that can be redirected to assist you. All puzzles seem to be solvable without having to look for a walkthrough (based on my average intelligence, notice i'm not using the word "above"). If you liked the first Portal, chances are you will like this game. There is also a multiplayer mode now which I haven't had a chance to try out but seems like it would be fun as well. Like the first game, it seems to finish quickly but is still worth the money in my opinion. I know many games are moving towards using the STEAM software installation method, to say the least it is very annoying. Basically you purchase this game which installs STEAM on your computer, then you go to the STEAM site and download the actual game from there. Takes quite a while to do. Understandably they do this to keep their software from being copied illegally. Still a great game.