Fan films are a sometimes fascinating subgenre, especially with digital effects getting cheaper and cheaper to realise, and this particular fan film takes one of the most distinctive games ever made and actually manages to capture the oddball mood. There’s a reason why computer gamers go into complete geek-pleasure mode over Portal – it was an out-of-nowhere surprise, an experimental quickie project released to bolster up the Orange Box compilation (and make up for it taking so long for Half Life 2: Episode 2 to get released) that managed to get almost universal acclaim for its brain-twisting 3-D puzzles and its pitch-black humour. Built around a simple mechanic – with a gun that fires portals at walls (allowing you to put an entrance or an exit into a whole variety of locations) you navigate a series of increasingly difficult puzzles set by a derranged computer – it’s a short but perfect example of atmosphere, storytelling and gameplay.

I recently got to play Portal 2, the full-length sequel, which is rather as if someone took a quirky indie SF film and made a $200 million dollar sequel that’s bigger, bolder and in many cases much broader in humour – and yet still manages to carry off the unique atmosphere of the original. It’s a brilliant, hugely engaging game and also shows careful hints at a bigger backstory, while leaving us on a sort-of-cliffhanger. This fanfilm I’ve spotted is set after Portal 2’s ending, and while it doesn’t really have a story and is more of an exercise in mood, it’s incredibly well realised, and the opening sequence has some genuine “Oh my god!” moments for any self-respecting Portal fan. If you haven’t played the game, this won’t mean anything to you – if you have, sit back and enjoy ‘Outside Aperture’…