Even though it’s built with the Half-Life 2 engine, you won't launch rockets at waves of enemies or find any online death matches in Portal. Although it certainly looks like a first-person shooter and controls like one, Portal is best described as a first-person puzzler. But juicy details regarding this upcoming mystery wrapped in an enigma have been far and few.
Luckily, we got to wrap our brains around a level from a demo of the game. While it may not be the "groundbreaking action game that will forever change the way gamers interact with their environment" that developer, Valve says it will be - Portal will definitely open your minds with some creative and fun gameplay elements.
Each level in Portal is broken down into a series of brief puzzles requiring you to make use the "Aperture Science Handheld Portal Device" (ASHPD). With the ASHPD, you can launch up to two portals onto any flat surface - creating a physical doorway that connects the two areas.
In one area, we had to cross a giant chasm that was too wide for us to leap across. In order to cross, we had to fire the ASHPD to create two portals on either side of the room. After crossing through the portal at the room's entrance, we emerged on the other side of the chasm, and proceeded to the next area.