So much more than I expected
I knew Portal was going to involve puzzles that had you move yourself and other objects around by placing the two endpoints of a portal, but I wasn’t expecting to be hilariously insulted by a robot overseer and notice tie-ins with the Half-Life series. While the portal gun is great fun by itself, what really makes this game is the writing. It’s so much more fun to accomplish something and then be cut down by the sarcastic voice of your only companion (besides that cube with the heart on it, which you murdered). It also features the greatest end-game song of all time (well, at least the best at the time).
It’s not just thinking that gets you through the test chambers either — some of them also require the agility to get the timing just right. You can almost feel the wind in your hair as you drop into a portal and fling yourself across the room, firing a new set of portals before you land.
There are also two other modes besides the campaign that I don’t totally remember. One was the same test chambers slightly modified to be more difficult, and another was challenges to solve the chambers with only a certain number of steps / portal placements / etc. Portal is one of the first games to feature Steam achievements, so that potentially gives you a couple more things to do.
The main downside to Portal is that it’s not very long. The Orange Box pricing still made it a great deal but it’s difficult to be introduced to the portal gun but only have 19 test chambers to use it in. There are community-created test chambers to download and try out, but you need to know the correct place to put the files and how to load them — I never tried any.