One of the joys of attending a film festival is the sheer diversity of the product on offer.

Short of snuff or hardcore porn, pretty much any genre is catered for at these things. Want to see a film about giraffes taking over the world? Chances are there’s a movie you can catch where that’s the main plot point. Probably.

That’s why a trip to the local multiplex is such a soul-crushing experience. I remember when Darren Aronofsky’s The Wrestler (an Oscar-nominated film, so hardly arthouse fodder) came out a couple of years back and I asked at my local cinema whether they would be getting it. I received a shake of the head from the staff member I spoke to, the kind of vacant head movement that basically transcribes as “What the f*ck are you talking about?”.

Now if I’d asked how many screens Transformers would be playing on I’m pretty certain I would have been given a forensically detailed response. I guess the moral of the story is if you like films, suck it up and be prepared to clock up the miles as I don’t see the attitudes of cinema chains changing any time soon, especially now that 3D’s here. But that’s another rant altogether.

Variety’s the name of the game at festivals, though, and I was looking forward earlier today to what would probably be the most varied day of the festival for me.

The day would start off with a screening of Constantin Popescu’s debut feature Portrait Of The Fighter As A Young Man, a challenging account of a group of Romanian freedom fighters slowly being ground down as the Soviet invasion of 1944 takes hold.

After some rather grating problems with the trains, I made it to Leicester Square just in the nick of time only to discover the film had been pulled due to a dodgy print.

Although momentarily frustrating I quickly got over it which is more than can be said for one mouthy gentleman who walked around the cinema foyer waving his ticket around shouting overly-loudly “I want to speak to a manager!” as if he’d just found out his house had accidentally been sold to a family of Polish farm workers.

London’s a big city, though, and there’s always something you can do to soak up a couple of hours. For me that involved drinking a couple of cups of tea and keeping out of the rain. I know, bananas.

Anyway, at least the second half of my film-going day didn’t suffer the same fate and I was able to enjoy Geoff Marslett’s Mars in all its slacker glory.

It’s probably fair to say there hasn’t been anything like Mars before, so as a piece of film-making it’s certainly one of the most original I’ve ever seen.

The most visually arresting thing about Mars is its use of rotoscoping, the technique of animating over live action film movement that was made famous by Ralph Bakshi in his stab at The Lord Of The Rings in 1978 and most recently by the godfather of mumblecore Richard Linklater in Waking Life (2001) and his take on Philip K Dick’s A Scanner Darkly (2006).

The benefit of rotoscoping is you can pretty much create any background you want and make it look like real people are interacting with it. In the case of Mars, Mark Duplass, Zoe Simpson and Paul Gordon play the crew of the first manned mission to the Red Planet.

This is the kind of slacker misfit crew we saw back in John Carpenter’s debut feature Dark Star (1974). Apart from the regular TV updates to a disinterested Earth, Charlie (Duplass) can barely see the point of him being there, while mission commander Hank (Gordon) grows more bored about the prospect of setting foot on Mars the closer they get.

But instead of most films of this ilk, which tend to show the crew getting more fraught with each other and the tension build as things go horribly wrong, the crew form a tightening bond and, when calamity strikes, pretty much take it in their stride as if they’re making a cup of tea.

It’s this refusal to adhere to the confines of the genre where Mars really clicks, that and the constantly witty script, delivered in an arid, deadpan fashion by all three.

The fact that life is discovered on Mars is hardly surprising, but the source of that life is irreverent, stupid and kind of makes sense all at the same time. Let’s just say that Britain’s failed Beagle II probe to the Red Planet serves its purpose after all.

A great soundtrack by Howe Gelb adds to the underground cool of Mars, as does the casting of cult singer songwriter Kinky Friedman as the most unlikely US President you’ll ever see. Mars probably won’t ever escape the festival circuit, but if you get the chance check it out on DVD. It sure as hell beats Mission To Mars.