Earth Must Die's stellar comedy cast and novel 'no touching' point-and-click twist make for a bawdy sci-fi treat, despite some fumbles

Imagine sitting down with EA Sports FC and discovering your diddy little soccer-man doesn't want to kick the ball, or firing up your favourite FPS and finding your avatar's developed an aversion to guns. And what if Mario suddenly said no more turtles near his bottom? Chaos would ensue! But that's pretty much where we find ourselves in Earth Must Die; a point-and-click sci-fi comedy adventure from acclaimed studio Size Five Games that doesn't even bother with an inventory because its protagonist - VValak Lizardtongue, Grand Shepherd of the Tyrythian Empire - refuses to touch anything.

It's a novel design choice and one that immediately sets Earth Must Die apart, introducing an interesting dynamic to its more familiar point-and-click rhythms. Early on, for instance, amid a chaotic rebel incursion, VValak must engineer his ascent to the Tyrythian throne - not through force but by talking his twin older brothers into murdering each other. As protagonists go, he's just deliciously awful. But 300 years on, his tyrannical reign is not going well; Tyryth's reserves of Fabriconium are so low the planet can't even repel mosquitos. And, with a certain blue-green planet now on his radar, there's worse to come. VValak must find a solution, which, given his insistence on that whole 'no touching' thing, means a lot of indirect manipulation.

Pretty much every obstacle VValak faces in Earth Must Die can be solved through conversational coercion. Rather than spending your time hoovering up endless miscellanea with unknown purpose (as you might ordinarily do in these kinds of games), you'll charm, threaten, and trick characters - or, occassionally, voice-activated appliances - into doing your bidding, perhaps by craftily deploying information cunningly extracted elsewhere. And if you ever reach a conversational impasse, you'll find even more new avenues to explore and exploit by consulting the extensive lore database stored within VValak's gold-teated childhood nursing bot, Milky. Earth Must Die doesn't entirely jettison the genre's familiar conventions - you'll still spend your time plodding and clicking around the world looking for environmental hotspots that someone will need to interact with - but this is very much a dialogue-first kind of game.

Which would be a disaster if the writing was rubbish, but Size Five - the studio behind the acclaimed likes of Lair of the Clockwork God and Time Gentlemen, Please - has fine form when it comes to comedic point-and-click adventures. And Earth Must Die carries on that tradition, delivering a very British slice of absurd menace that's part dystopian satire, part Carry On film. There's a hint of Terry Pratchett, perhaps, in its elaborately whimsical world-building - browse Milky's Milkipedia, for instance, and you'll unearth lengthy entries on everything from Tyryth's powerful Orgymakers Guild to a species capable of turning into the thing most likely to amuse passersby to distract them from killing it. There's a touch of Douglas Adams too, especially in its vision of a bureaucracy stunted future (Earth Must Die's entire first act revolves around an increasingly convoluted attempt to push a button). And there's a sly intelligence beneath its frequent dick jokes and silly flights of fancy as it squeezes in some pointed observations about power - you're playing a fascist dictator after all.

It's good stuff, but it's not just the writing that sells Earth Must Die's whimsical dystopia; it looks and sounds great too. Those wonderfully kinetic backdrops and expressive animations are packed with character - a little bit classic LucasArts, a little bit Adult Swim - and its attention-grabbing cast list (crammed with contemporary British comedy talent including Matthew Holness, Tamsin Greig, Alex Horne, and Mike Wozniakis) is a real coup. It doesn't always work - the switch from professional voice actors to comedians with limited acting experience can be jarring - but the bulk of the enthusiastic cast acquits itself well. Plebs and Game of Thrones actor Joel Fry has a particularly tough task keeping on top of Earth Must Die's freewheeling script, but his VValak (sounding eerily like What We Do in the Shadows' Nandor) is enormous fun.

All of which might suggest an unequivocal slam dunk, but five hours in, I'm not completely sold. Chiefly, that's down to the puzzles, and the sometimes elusive logic that drives them. For the first few hours, it's all pretty straightforward - so much so, I was starting to suspect that in stripping away so many familiar point-and-click conventions, Size Five maybe hadn't left itself enough to play around with in order to keep things interesting. But after a certain point, there's a sudden swing in the other direction, and its increasingly elaborate puzzle chains become noticably cleverer and far more creative (here's looking at you, gory teleportation incident and subsequent orgy infiltration). But it also feels - and I'm still not sure if it's because I'm just not locked onto its wavelength, or if it's down to more specific design fumbles - like there are just a few too many information gaps and moments of unintuitive sequencing, leaving me blindly fumbling, trial-and-error style, my way through.

But it says a lot about the sheer quality elsewhere in Earth Must Die that, between the pockets of frustration, I'm still enjoying muddling forward. It's fun to be bad, and it's funny to play a villain struggling to suppress his villainous urges in the name of desperate, exasperated diplomacy. But more than anything, it's fun to surrender to Size Five's bawdy tangle of unpredictable satire and silliness - I've seen pulsating orifices here amid the nano-sized police states and shadowy string-pullers you wouldn't believe! And, honestly, how can I stay mad at a game when it includes bugs who vibrate so violently during their sexy mating rituals they've been harnessed into world-destroying bombs? Just remember: no touching.