I played HL2 many moons ago, but never got around to getting EP1 & 2 and Portal. From what I've heard they are all relatively short so I couldn't justify the $50 Orange Box and buying them seperately cost even more (I don't care for MP much anymore so Team Fortress did not fit into the buy equation). Ran across a Gogamer 48HR special and got the Orange for $30 which is a good price since its $10 per game.
Portal took about 3.5hrs and I got stuck twice. Both were because it took me a while to get the timing right. Once I knew what to do but couldn't do it, another time I hadn't quite thought of the right thing though I was on the right track. It was a good game but I don't think it was GOTY as many said. I did like the focus on puzzle aspects instead of normal combat situations in FPS.
While I understand the levels are set up a certain way to teach you what to do next, the change in mission length seemed to jump drastically. The earlier missions were super short then at about 15 or so got a lot longer all of a sudden. The last mission was super long and the best part of the game. Up until then I thought it was decent but didn't get all the crazy reaction of how great it was from other players. While that last level pushed it up to a good game it didn't make it GOTY (I think STALKER holds that place but I dig post-apoc). If there had been more after that then maybe GOTY, but I guess thats what Portal 2 will be for.
I did like the atmosphere of game. The labs seemed nice and sterile. Then you slowly see some back office areas which are a little more cluttered. Squeezing out of the lab you get to see the dingy behind all the nice shine. I will say I wasn't expecting the ending (Had luckily stayed away from spoilers so had no context when reading the games quotes "The cake is a lie!"). I also enjoyed the tester's voice and the little speaches she gave.
Since it was short I do plan on replaying with the developer commentary, something I never do. I am also going to try out the advanced maps that came with the game. Now I just need to play EP1/2 but think I might replay HL1 and 2 first once I clear out some other games.