Once in a while (but unfortunately a bit too seldom) you have the pleasure of playing a new game where the innovation really shines through and you can't help it but smile over the makers' creativity. With the large number of follow-ups and a game industry that, to a large extent, is defined by numbers and figures it takes courage to head down new roads, and so it's nice to see Valve's choice to include Portal in their Orange Box since it is a showcase of innovative gameplay, mixing puzzlesolving with the Source Engines abilities in physics.
The game takes off with the player waking up in some sort of lab and a female robotic voice guiding the player into the game. The voice is GLaDOS (Genetic Lifeform and Disk Operating System) and as you will see through the game "she" is an important part of the story and might even be a candidate for game character of the year. It doesn't take long before you get your hands on a Portal gun enabling you to create your own portals, which is necessary in order to advance through the various test chambers. To begin with the levels are obvious and easy to figure out but the difficulty increases through the 11 chapters, yet you never seem to be helplessly stuck.
The levels in Portal is wisely constructed and requires the player to understand the physics fully - objects, for instance, will retain their speed through a portal allowing the player to take advantage of that and launch objects or herself with great force. It can be somewhat confusing when you see your character mirrored through the portals, and from time to time you catch yourself experimenting with this instead of actually trying to solve the puzzle at hand. This, together with the sense of humour, is exactly why the game is so charming.
Each level (i.e. test chamber) is fairly short and once you've figured out the solution you get transported to a new test. The 11 chapters in Portal doesn't take very long to complete depending on how fast you catch on to the gameplay, but without revealing too much of the story there's a very neat gameplay twist about half-way through the game worth looking forward to. When you've completed the game there's still more challenges. In the main menu a series of bonusmaps, where you can choose to complete selected maps on time or with as few portals as possible etc., are unlocked and there's also maps altered to make the puzzles even more difficult to figure out.
Besides this, it's possible to play the chapters with developer commentary, so you can hear the thoughts of the devlopers at Valve while playing. Not all of the information is equally interesting but it's a nice little bonus - it does, however, become a bit annoying that GLaDOS can still be heard when playing in commentary mode as she can easily drown the developers' voice.
Graphically Portal isn't spectacular, but it is, however, not a game aiming to impress in this area. Several textures around the maps looks kind of old, but Portal does appear nicely if you have a computer which can handle a high resolution and detail level. Especially the open Portals can be demanding of the hardware (since you can see everything through them), but this is in fact a very nice effect which is crucial for the gameplay.
Portal is really well thought out and at the same time addicting. You constantly have to try and figure out one more level and throughout the game you get several aha-experiences that keeps you going. Another motivating factor is the connection between the Aperture laboratory where the game takes places and the rest of the Half-life universe, and the gameplay twist makes Portal reach a higher level even though the game is short.
Portal is a part of Valves Orange Box which also includes Half-Life 2, the expansion Episode One and the new Half-Life 2: Episode Two as well as Team Fortress 2.
Read our review of Episode Two here.