I have a great fondness for Valve's game-making sensibilities. First of all, both games have commentary. I love, love, love audio commentaries on movies; I was born for the age of the DVD. So to have two games that are great games in-and-of-themselves but that also have audio commentary for feature junkies like myself--it's just awesome-sauce.
You get a nice little glimpse of the way they go about creating software. Some of it is technical, like the way they meshed up physics in Portal or the way they textured cars in L4D that gave enough variety but didn't overtax their "texture budget". A lot of it is more practical, like the orange jumpsuit in Portal designed to make the character stand out against the sterile backgrounds. And some of it is simply philosophical. For instance, Left 4 Dead is a spoof of zombie apocalypse movies, and it never forgets what it is or tries to take itself too seriously. Similarly, Portal never tries to make GLaDOS scary. Throughout the first 2/3 of the game, GLaDOS seems genuinely ambivalent as to whether you live or die, even while you find yourself in strangely perilous situations. So when she finally does actively try to kill you, it has some weight. Both games spend a lot more time trying to be funny and fun than trying to be "cool". And the result is a game that is extremely cool and well-received (as compared to many of the shooters out there that try desperately to be cool but come off as laughable).
There are some similarities in the way the games were developed. Both were over-written--there's a lot more story in there than either game lets on. It's hinted at, but never explicitly told, leaving the player to discover and ignore as much as s/he chooses. It also means that there will be plenty more story to tell in sequels and that it will follow naturally from the originals (rather than feeling tacked-on). The games are noticeably free of cut-scenes. Any storytelling happens during gameplay, rather than interrupting it. Also, both games were extensively play-tested. Valve spent a week developing a working model of L4D and then 3 years testing and tweaking it. So both games are instantly playable by novices but can still be enjoyed by experts, and both do a good job of leading you to the exits without maps or arrows or every leaving you feeling lost.
And then there's the trivial and the minutiae. Some highlights:
- L4D was born while Valve were working on the bots for Counter-Strike: Source. They discovered that it was immensely fun to pit a couple guys working together with machine guns against thirty or forty bots with melee attacks. So they decided to build a game around that concept, and "zombie apocalypse" seemed the most apropos, conceptually.
- In Portal, backgrounds are squared and interactive objects are rounded, making them instantly distinguishable. Elevators, doors, buttons and portals are round. Even cubes have rounded edges and circles in their design.
- Because the focus on L4D is replay-value, many aspects of it are randomized, including enemy-spawning points, item-locations, dialog and music. This randomization inadvertantly made development easier because map changes were automatically populated by the game's virtual "director".
- The voice actress who plays GLaDOS is an operatic soprano.
- L4D uses lights and colors to guide you along the correct path. Safe houses and items are warm and saturated and the correct path is better lit than the detours are. Even though the levels are linear, they feel open because the player intuits the way from subliminal clues rather than being forced there by walls and obstructions (although there are plenty of those too). Similarly, hero characters have a warm, saturated look while the infected are desaturated and flat, making it easier to distinguish friend from foe.
- Several levels in Portal are there to train you to do simple things without overtly insulting your intelligence. Level 03, for example, supposedly introduces you to the "pit", but in reality it teaches players that portals are bi-directional. Play testers seemed to get stuck on the idea that blue was always an entrance and orange was always an exit, but the stagnant orange portal in the center of the level must be used as both an entrance and an exit in order to proceed.
- Both games are designed to prevent fatigue by mixing a couple basic schemes of play. Portal is constantly switching between simple timed puzzles and more complex strategic puzzles. L4D breaks up the keep-advancing-and-shoot-everything-that-moves dynamic with boss zombies that you want to either avoid altogether(e.g., witches) or pick off from a distance (e.g., boomers) and instances throughout each campaign where you have to dig in to a prepared defensive position before you can advance any more.
I guess this means I'll have to try Half-Life at some point.