I remember a simpler time in the Half-Life universe. When Gordon Freeman was just a lowly physicist. When "Barney" referred to an entire class of security guards rather than a particular individual. A time when the only transdimensional alien attacks were relegated to one specific area and affected all present in totally different ways.

Opposing Force, the first Half-Life single player expansion, retells the story of the Black Mesa Incident through the eyes of one of the soldiers called in to cover up the incident by exterminating aliens and scientists alike. Playing as marine Adrian Shephard, the player fights through different sections of Black Mesa and occasionally runs into some familiar faces along the way.

I bought this game when it first came out, but even then it didn't occur to me how goddamn cool the idea was. Rather than adding on some boring extra missions with Gordon as the protagonist, Gearbox decided to revisit the same incident from a totally different perspective. It's a gimmick I thought I'd see a lot more of as time went on, but that hasn't been the case as such. Which, of course, makes Opposing Force all the more precious.

Story:

Adrian Shephard (i.e., you) are sent in with a military team to clean up the mess at Black Mesa. As you approach the facility, however, your helicopter is shot down and mission "kill all scientists" is quickly abandoned in favor of simple survival.

On the one hand, this story is really cool -- it makes us feel a great deal of sympathy toward at least one of the brutal military douchebags Gordon had to annihilate en masse during the original Half-Life, but on the other hand it's still kind of a cheat. We hated the military goons in HL because they were needlessly killing scientists: we like Adrian simply because he doesn't do that due to his new survival objective.

While a game following what it would have really been like to be one of the military guys could have been either really depressing or needlessly sadistic, I think it would have been interesting to at least show some sort of character arc for Adrian. Say, what if the plot started with Adrian doing his job and the player being ordered to exterminate scientists (which, presumably, the player could opt not to do but risk harm), and only afterward turned into a typical survival story? As it stands, we pretty much like Adrian Shephard from the beginning of the game, where the plot had the potential to make him a much more complex character.

Still, it's really awesome to see the Black Mesa incident from another perspective, and just plain cool as hell to catch odd glimpses of Gordon and the G-Man as Adrian goes about his mission. Without a doubt, OF's greatest moment comes when Adrian enters a chamber just in time to see Gordon sprint into the Xen portal. One is tempted to (A) shoot at Gordon just for fun and because it's awesome, and (B) warn Gordon not to go because that section of the game kind of sucks ass.

Gameplay:

Opposing Force includes pretty much identical gameplay to that of its predecessor, save for some badass weapon replacements (a colt turns into a desert eagler, a crowbar turns into a godlike BioShock-esque wrench), new alien enemies, new support characters with specific abilities like demolitions or healing, and obviously new levels. So, in retrospect, I guess it did change a lot.

Perhaps it's just me, but I found the new weapons in Opposing Force to be a lot sexier than the old ones. Nostalgia obviously dictates that I now prefer the crowbar to the wrench, but at the time I remember really preferring the badass machinery Adrian got versus Gordon's comparatively lackluster arsenal.

Structurally, nothing really differentiates OF from HL apart from the fact that it's much shorter. You still get from A to B by helping scientists, and you still engage in a rather silly and bombastic endboss fight against a huge alien.

Why you're probably not playing it:

Because it's not as good as the original Half-Life, which is subsequently not as good as Half-Life 2, which is subsequently not as good as Half-Life Episode One, which is not as good as Half-Life Episode Two. On the Half-Life ladder of quality, it's only slightly above Blue Shift in terms of fun factor, and at the moment it would appear that Adrian Shephard's story isn't going to intersect with Gordon Freeman's again anytime soon.

This is kind of a bummer, as Adrian's ultimate fate is left so vague that one just can't help but want to see him again. He's "detained," yeah, but for how long? Until when? What does the G-Man want him for? It'd be really goddamn cool to see him pop up in one of the new HL2 episodes, but given the fact that Valve took great pleasure in intentionally cockteasing the fans in Portal by highlighting the keyboard letters for "ADRIAN SHEPHARD" on every desktop computer, drawing more attention to the red herring that the "Aperture Science Handheld Portal Device"'s acronym is "ASHPD," which sort of looks like how someone would pronounce "Adrian Shephard" if they really hated vowels.

Still, regardless of whether or not he ever comes back (he probably won't, though he could do a hell of a lot of damage to the Combine if anyone let him), it was still fun to have him around as a different perspective on the Black Mesa Incident.