Steam, Valve’s digital video game distribution system, is the most important thing to happen to PC gaming since the advent of graphics cards. Besides providing a more direct link between developer and consumer, Steam has helped realize the possibility of episodic gaming. Though they don’t quite have the timing down just yet, Valve has been able to shift its focus from large, ambitious projects to smaller, more daring titles. With The Orange Box, Valve has bundled four of these episodic games – three new, one old – together with Half-Life 2, and has created a product with a volume of content matched only by its creativity.

Everything about The Orange Box is fresh and surprising, from the imagination on display in the games included, to the unexpected Steam Community features. The Orange Box is a title that inspires hyperbole. And actually deserves it. Simply put: The Orange Box is the greatest gaming compilation in the history of the medium.

Half-Life 2: Episode Two is perhaps the most anticipated game in the collection. It begins immediately where Episode One left off, finally leaving City 17 behind in favor of subterranean antlion hives and the wide, open riverbeds of White Forest. The more natural settings are a welcome change of pace after two games dominated by urban environments, and instill the series with a newfound sense of originality, even though the Source engine is now three years old. It still looks as fantastic as ever, though, even on relatively ancient PCs, and improvements to the engine’s particle and lighting systems, as well as some improved key character models, allow it to really shine.

More than just another pretty face, Episode Two proves that Valve is unmatched in the video game arena when it comes to pacing. Epic combat events are offset by smaller encounters and quiet, solitary moments, while a clearly defined final objective drives the action forward. Gameplay is equally varied, with plenty of physics-based puzzles and environmental obstacles to overcome between firefights. Vehicles return in Episode 2, with Alyx and Gordon spending about half of the game in possession of a beatup muscle car. While it has no weapons of its own, it comes equipped with a radar display detailing the locations of hidden weapon caches, adding some non-linearity and rewarding exploration to the game. Valve has greatly refined their vehicle controls since Half-Life 2’s release. Gordon’s new ride is much more responsive than his buggy or hovercraft ever were; using this new vehicle feels empowering rather than limiting.

Episode Two is the most story-heavy Half-Life game to date. Non-interactive cutscenes and lengthy conversations are spread throughout the experience with careful attention to pacing, always leaving you thirsty for the next story event, but never fatigued from too much storytelling. At this point, Valve really knows how to do Half-Life well, and Episode Two is handily the best game to bear the name yet. Playing through the game takes about five hours, and by the time you reach the game’s stunning finale, you’ll be chomping at the bit for Episode Three. Here’s hoping we see it before 2009.

Thankfully, The Orange Box contains many other goodies to keep you entertained until then. Developed by the same group behind Narbacular Drop – the team’s senior DigiPen project – Portal incorporates all of the elements found in the original game, building on this foundation to create one of the most memorable gaming experiences in recent memory. Armed only with the Aperture Science Handheld Portal Device – a weapon capable of producing blue or orange portals by pressing the left or right mouse button, respectively – you must overcome a series of increasingly difficult, brain-bending puzzles. By placing portals on a floor, wall, or ceiling, you can enter one portal and instantly exit the other. Portals aren’t teleporters, however; they are doorways. As such, you can carry objects through the openings or use them to transport materials too dangerous for you to handle directly. Momentum is also preserved through a portal’s threshold, leading to some especially dizzying (and fun) puzzles in which you must use precisely placed portals to fling yourself across otherwise untraversable pits.

The game plays out through a series of puzzle-laden test chambers that stretch the possibilities of this portal mechanic to its limit. It begins slowly, teaching basic mechanics before handing you direct control of the portals themselves. Up until the end, the game continues to introduce new elements, forcing you to rethink the possibilities of the portals or execute complex maneuvers in rapid succession. The game is always challenging, but never frustrating, layering seemingly simple procedures into intricate tests of skill. Portal may only be three hours long, but advanced maps that rearrange previously completed test chambers and extremely difficult challenges that place strict limits on the number of portals you can use, steps you can take, or the overall time will keep you busy for many hours after the amusing credit sequence.

You’re not entirely alone in Aperture Science’s sparse test chambers. Besides a loveable companion cube, the snarky, sarcastic female AI GLaDOS provides her running commentary on your progress. She gives life to the otherwise sterile environments, and her clever quips act as additional reward for a job well done, playing at the beginning and end of each test chamber. The writing in Portal is genuinely excellent; GLaDOS’ dialogue is simultaneous laugh-out-loud funny and uncomfortably unnerving. Like Half-Life, much of the storytelling is relegated to the gameworld itself rather than expository cinematics, and before game’s end, Portal connects to the Half-Life universe, and Episode 2 in particular, in an interesting way.

Hopefully this isn’t the last Portal game we see. Despite its short playtime, Portal alone is worth the price of The Orange Box, standing out as the most uniquely interesting title in a package saturated with excellence. An innovative, mind-altering experience, Portal will leave your head aching and your palms sweating. Combined with the full force of Half-Life 2 and its first two episodes, Portal and The Orange Box makes for a meaty single player experience, but you’ll spend just as much time, if not more, with the game’s multiplayer component.

Just as Half-Life 2 originally shipped with an updated version of Counter-Strike, so does The Orange Box come bundled with a greatly refined sequel to Team Fortress Classic. Team Fortress 2 is a game whose development has taken on an almost mythic quality. The game has been in development since 1998, and many thought it would join the ranks of Duke Nukem Forever as much-hyped vaporware. Bearing little resemblance to the ultra-realistic military shooter Valve first announced, Team Fortress 2 lives up to its massive hype and delivers a satisfying multiplayer experience.

Streamlined and simplified, the game hasn’t traded accessibility for the richness that made the original so engrossing. Individually, each of the nine classes is easy to pick up and play, but mastering their strengths and weaknesses, and learning how best to apply their unique abilities to best benefit your team, takes time. Regardless of your playstyle, however, you’ll find a class (or nine) that aligns with your tastes. The engineer is a great defense class, able to build powerful automated turrets and teleporters to transport members of your team to the frontlines more quickly; the flamethrower-wielding pyro lacks range but excels at close quarters combat and ambushing players around corners; and the medic is a master healer able to build up invincibility charges that he can apply to other players, to name but a third of the game’s playable roster.

Besides offering a unique play experience, each character also sports a distinct personality: the sniper is a suave Australian hunter, the demoman a drunken Scotsman. All of Team Fortress 2 oozes character. Set in a timeless, over-the-top spy fiction, the game takes visual cues from Normal Rockwell and other mid-20th century artists, utilizing a toon-shading effect that creates sharp contrasts between light and dark. Besides the distinct visuals, the game also utilizes a dynamic dialogue system, allowing characters to react to in-game events with no input from the player. The net sum of these parts is a game with a distinctive visual style and a great deal of charisma. Team Fortress 2 has a welcoming charm that makes killing fun again.

Initially, Team Fortress 2’s speed and frantic nature comes off as sheer, uncontrollable chaos. But the more you play it, the slower the game seems to become. There’s a great deal of depth hidden behind a veil of seemingly chaotic ruckus, and once you take the time to learn the workings of the game, Team Fortress 2 makes for an incredibly rewarding diversion. Each class represents a separate, infinite learning curving. Like many online games these days, Team Fortress 2 includes an exhaustive stat-tracking feature, but here your statistics are only compared against your own. As you play the game, you see yourself getting better and have the numbers to back up your assumptions; the game becomes as much about besting your own accomplishments as beating your opponents. Even ignoring such a thorough stat-tracking system completely, Team Fortress 2 is remarkably replayable, and offers enough depth and variety to keep you glued to your mouse and keyboard for months.

In addition to the five games included in the package, The Orange Box also includes a host of meta features. Steam Community features such as achievements for all three of the new games and a universal friends list adds a tremendous amount of replayability to the games. Seeing your friends hop into Team Fortress 2 will have you follow suite, leaving Episode Two achievement chasing for another day. All of the episodic content, Episode One included, come with impressive commentary modes, providing interesting insight into the development process behind each of these great games.

Even if you already own Half-Life 2 and Episode One, The Orange Box is a necessary purchase. Portal, Episode Two, and Team Fortress 2 alone represent a wealth of content unmatched in any other first-person shooter. For those lucky few new to Half-Life 2 or new to the series in general, The Orange Box allows you to play through the first three entries in the Half-Life 2 saga with no years-long interruption. Sure, the improvements to the Xbox 360 version of Half-Life 2 aren’t present on the PC, and Valve could have thrown in the original Half-Life and had the entire series so far included in a single package, but the simple fact is that, all hyperbole aside, The Orange Box is one of the greatest, most content-rich games ever produced.