It's normal to be wary of licenced games. More often than not they're shoddy rush jobs, farmed out to a studio's B-team to capitalise on the release of a film or TV show. But The Stick of Truth is an oddity in that it's not only faithful to the material, but good too. You really couldn't ask for a better South Park game. It looks and sounds identical to the series, and is just as gleefully offensive. But it's also a very decent RPG, with rich customisation and slick turn-based combat.

You are the new kid , and you've just moved to the not-so-sleepy Colorado mountain town of South Park with your parents. There are enough bits and pieces in the character creator to make a fairly accurate depiction of yourself, and I enjoyed seeing a little paper me sharing the screen with Cartman and co. in what is essentially an episode of the show. Don't worry about what name to enter when you're given the chance, though—everyone refers to you as 'douchebag' regardless.

From the start, most of South Park is free to explore. Wandering its streets and plundering its houses, I was struck by how detailed it is. There are secrets, sight gags, and show references everywhere , and thorough exploration is rewarded with weapons, costumes, and other useful loot. It's a big space, and nearly every building can be entered, from Tom's Rhinoplasty and South Park Elementary, to the houses of all the main characters. The whole game is dense with jokes and Easter eggs, even down to the hundreds of sellable junk items. A lot of love has gone into designing the world.

As you explore your new home you're drawn into a clash between the humans, led by grand wizard Cartman, and the elves, led by... well, I won't spoil the surprise. Cartman recruits you into his army and you're given a selection of classes to choose from: mage, fighter, thief, or jew. Yes, really. Each has its own special abilities, but there are no limits to what armour and weapons you can equip. The two factions are fighting over the titular Stick of Truth, a mystical artefact of great power that, according to the kids, allows the bearer to the control the Universe. But really it's just a stick.

The writing is what you might expect from a South Park game. It's crass, it's satirical, and its parodies—of video games, RPGs, and high fantasy—are keenly observed. Nothing is out of bounds for Matt Stone and Trey Parker, and the game will no doubt stir some controversy. But that's why South Park exists, and I'd be disappointed if it didn't . The show has been ruffling feathers for almost 20 years and I'm glad the game hasn't pulled any punches. A few scenes in the PC version, including Randy Marsh being violated by anus-probing aliens, are censored in certain regions, but they amount to a fraction of the game. I'd consider some of the stuff that wasn't cut to be more controversial.

The war over the Stick gives way to a larger story involving a UFO, a government cover-up, and a virus that turns people (and kittens) into Nazis. But there are opportunities to stray from the story in the form of sidequests. You'll help Al Gore hunt down the elusive ManBearPig, fight Mongol warriors in the Tower of Peace, reunite Mr. Hankey with his missing kids, and dozens of other distractions involving characters from the show. A few are 'collect X things' filler, but most are entertaining and reasonably lengthy, with rewards including the ability to summon, among others, Jesus to help you in battle.

The combat is where Obsidian's involvement becomes clear. They're the studio behind the likes of Fallout: New Vegas, Knights of the Old Republic II, and the forthcoming Pillars of Eternity, so they have some RPG chops, which is evident in South Park's excellent turn-based combat. There's genuine depth here, with status effects, damage modifiers, stances, buffs, debuffs, and customisable gear. It's most reminiscent of the Final Fantasy games, but with a South Park twist. Fling a turd at an enemy and you'll inflict 'grossed out' status, causing them to keel over and puke, while red-headed enemies' 'Touch of the Ginger' ability lowers your defence. It's snappy, fast-paced, and requires some strategic thinking, but bar a few bosses, it can be a little too forgiving on the default difficulty setting.

Real-time elements give the combat some added flavour. You can block by hitting the right mouse button just as an enemy attacks, and most spells and abilities involve some kind of player input to pull off properly, usually in the form of simple, unintrusive minigames. To use Jimmy's bardic powers, performed with his magical lute, you have to complete a short rhythm-action sequence, while the new kid's fart powers (think Skyrim's dragon shouts, but funnier) are timing-based. These make combat feel more hands-on and dynamic than your average turn-based game.

There's a lot of gear in the game, which greatly expands your ability to customise your character and comes with interesting buffs and modifiers. Combined with 'strap-ons', which add additional effects to weapons and armour, this gives you scope to make some unique character builds. As you face enemies with different strengths and weaknesses, you'll find yourself regularly changing costumes to adapt. Much of the fun in the game—that is, the RPG beneath all the jokes and pop culture references—lies in experimenting with the vast array of gear and strap-ons you find as you play. This might be the first time in PC Gamer history where the word 'strap-on' has appeared three times in a paragraph.

The problem with reviewing The Stick of Truth is that I can't really talk about my favourite bits. Being surprised is half the experience, and you won't believe some of the stuff it makes you do. I had to stop myself calling people over to my monitor in the office to see whatever ludicrous thing was happening next. It's one of the most unpredictable, and consistently entertaining, games I've played, which is all the more impressive when you realise that the only reused assets are enemies. Every scene is handcrafted and animated, which is remarkable for a game that lasts between 15-20 hours. The summons and late game special attacks, including one where Cartman overloads his V-chip by repeatedly swearing, are a joy to watch. They've somehow made the famously low-fi South Park feel lavish .

And I laughed. A lot. It's puerile, yes, but not in the dimwitted way the execrable Family Guy game was. South Park's humour has always felt very knowing to me, with its tongue wedged firmly in its bum cheeks. The show marries schoolboy fart jokes with dark, witty satire, and the game is no different. It also manages to steer almost entirely clear of the trap a lot of comedy games fall into, where they joke about something while actively making you do it. See Far Cry 3 spin-off Blood Dragon mocking boring tutorials while making you sit through a boring tutorial for a recent example. The comedy here is never at the expense of fun, even when it's poking fun at gaming cliches.

There are better RPGs out there, but no one's buying The Stick of Truth just for that. You'll probably buy it because you like, or at least are familiar with, South Park, and as an extension of that series it's pretty much perfect. That it's a decent game underneath it all too is a pleasant bonus. Above all, it's just a wonderful piece of entertainment. It's surprising, surreal, packed with jokes, and rarely frustrating. I didn't get bored once across the 17 hours it took me to finish the story and most of the sidequests, and it kept me laughing consistently until the credits. If that isn't worth 90%, I don't know what is.