Alright, hands up - who figured this out straight away, who did it randomly and who sat there feeling helpless until they had that required eureka moment? Portal 2 remains one of the funniest and most instantly-enjoyable titles on the market, thanks in no small part to The Office writer Stephen Merchant's voicing of Wheatley; a hilariously self-aware robotic companion that helped garner Valve plenty of awards for immaculate writing and game design. Come the latter half and Wheatley gets a taste of power thanks to some new upgrades, leading to a great little showdown where to finally save yourself you'll have to fire one of the inter-connecting portals all the way to the moon, the other half sucking the power-mad robot out into space. https://www.youtube.com/watch?v=usyYqJf0rfk The fact that you didn't realise the gun was even capable of such a thing is a jaw-dropper in itself, and as the whole thing plays out and you're left on earth with only GLaDOS for company, it's a fitting end that leaves things wide open for a Portal 3.