Metal Gear Solid 4: Guns of the Patriots is an incredible experience, the best game yet for the PlayStation 3 and a must-see finale to Hideo Kojima’s seminal, often celebrated (and occasionally reviled) stealth action series. But there’s a surprising degree of irony in the success of this last game, which is at its best in ways its predecessors conspicuously fell flat. If you haven’t played a lot of Metal Gear Solid before now, I’m talking about the gameplay here–the part where you grasp a controller and actively make Solid Snake creep around the shadows, stealthily snapping necks and infiltrating enemy bases to stop some nefarious plot or other.

That part has always been a little lacking. Truthfully, this is a series that you sit back and watch as much as you interact with it. Over the years, MGS has been buoyed by its high production values, well-crafted cinematics, and increasingly twisty, outlandish plots–even as its gameplay has typically lagged behind that of its contemporaries, with nonsensical mechanics and an awkward adherence to tradition making the games less fun to play than they ought to be. Before now, you would have recommended a Metal Gear Solid game to someone looking for a technically impressive and complexly plotted story of intrigue, but not a deeply satisfying action game.

Given that legacy, what a surprise it was to discover that Guns of the Patriots is not just the most playable game in this franchise but possibly the most graphically intensive and downright thrilling action game ever made. It’s the first game in the series to periodically remove your stealth shackles and actually suggest you plow through your obstacles with guns ablaze, and it does this with seriously explosive aplomb. There are sequences here that come close to fulfilling the promises of Sony’s famously overblown Killzone 2 trailer, in terms of their visual fidelity and the intensity of the action. I honestly had to remind myself more than once I was playing a video game and not a CG movie. If you’re playing this on an HDTV and home theater system, they’ll get a major workout.

It’s not all explosive shootouts and daring escapes, though. Stealth still rules here, and MGS4 is so much fun to play primarily because it’s finally caught up to modern gameplay conventions, with a controllable camera and over-the-shoulder and first-person aiming modes comparable to those of other great third-person action games. Sure, a few irksome vestiges of the old MGS remain–the rolling and crawling controls are clumsily similar to their forebears, for instance–but finally, it just doesn’t feel like a chore to control Snake.

Some of the new stealth toys–like the background-mimicking OctoCamo or your little robotic operating buddy the Metal Gear Mk. II–make the sneaking that much more fun to tackle. Then there’s the arsenal of weapons, which has to be the biggest, or at least the most extensible, yet in the series. It’s not enough that you can collect a mountain of assault rifles, submachine guns, pistols, and explosives–you can also slap on laser sights, flashlights, scopes, fore grips, and under-mounted grenade launchers and shotguns. It’s easy to get sucked into the weapons customization, which comes courtesy of a smooth-talking gun dealer named Drebin (who figures into the storyline too).

As nice as this mammoth arsenal is, it’s even nicer that the game actually encourages you to use all those guns. You can meticulously sneak your way through every scenario if you want, and in fact, there are specific rewards for killing few or no enemies. But in many areas a run-and-gun approach is equally viable and will often let you ally yourself with local militia fighting against Liquid Ocelot’s ubiquitous, nanomachine forces.

If you’ve been keeping up with the series, it won’t surprise you that stopping Ocelot and his plot for world domination after the events of MGS2 is your mission here. It’s not strictly necessary to have played every MGS game before now, but you should at least do some solid research on the previous games’ storylines before playing Guns of the Patriots if you want to pick up on most of the subtle details.

Plot-wise, the game breaks from tradition in a couple of important ways. For one, it’s not afraid to move the story ahead in time and geography, so you get multiple discrete acts that take place in far-flung locations around the globe. One of these acts offers a great dose of nostalgia for longtime series vets, though discovering what that act is all about is one of the greatest joys in playing the game. The other is the sweeping closure that results from the full disclosure of the series’ many secrets that occurs by the end of the game. If you’ve been wondering about the eventual fates of characters like Raiden, Eva, Vamp, Naomi Hunter, Meryl Silverburgh, and the rapidly aging Snake himself–not to mention the truth about the FoxDie virus, the shadowy Patriots, and the legacy of Big Boss–you’ll get them all gift-wrapped on a platter by the close of the game.

Anyone who’s played the previous Metal Gear Solid games will already know that to fully appreciate Guns of the Patriots, you must come to grips with Kojima’s unique brand of narrative outlandishness. The cutscenes here are no less frequent, lengthy, or indulgent than before; they’re rife with over-the-top, implausible plot twists, drawn-out exchanges of occasionally stilted dialogue, and character models who, for all their extreme realism, descend into that uncanny valley from time to time. But these scenes excite far more often than they drag. The game is also peppered liberally with Kojima’s trademark little post-modern touches, like references to you the player and the PlayStation 3 hardware, and a smart, quick flashback sequence toward the end that will be especially satisfying for series vets.

Kojima Productions saw fit to include an online competitive game aptly called Metal Gear Online. It’s not aggressively bad, but it’s hamstrung by MGS4’s mechanics, which work great when you’re competing against the single-player game’s AI but aren’t really tailored to combat against thinking opponents. MGO’s signup process is also needlessly byzantine, requiring you to create not one but two login IDs just to connect. There’s a good amount of game modes and maps in here, but Konami seems intent on nickel-and-diming MGO players in the future, since you already have to pay extra just for the privilege of creating more than one character profile at a time.

You could level some other minor complaints at Guns of the Patriots. The game stops to load a little too frequently, and it features not only an initial eight-minute install process but also several subsequent, shorter ones before each act. But none of the game’s minor blemishes are enough to detract from its massive overall impact. It’s the surprising entertainment value of the action, the mind-blowing visuals, and the completeness of the story’s conclusion that make this last installment so satisfying. Metal Gear Solid 4’s positive qualities make it one of the most significant game releases of this generation, and anyone with an appreciation for the evolving form of the medium would do well to play it from start to finish.