10 Secret Levels In Iconic Video Games You Totally Missed

4. Call Of Duty 4 - Mile High Club

Can you believe it's almost been a decade since Modern Warfare first came out? 2007 saw the industry get a heady dose of Jerry Bruckheimer-esque militaristic mayhem, and we've not looked back since. In amongst all the cheers and surprises at just how perfected Infinity Ward's take on a modern shooter though, was the fact its brilliant bonus level was almost completely overlooked - mainly because if we gamers have an option to skip credit sequences, we nearly always will. Regardless, to trigger this Mile High Club airplane stage, you simply need to finish the main campaign and sit through the entirety of the credits. It's an extremely gruelling hostage-rescue mission; one that if you flick the difficulty onto Veteran, asks you to complete it in just one minute. Infinity Ward did add a secret achievement if you can pull that off, but with so many enemies to take down and the whole thing ending in a one-shot 'save the hostage' showdown, it's truly the greatest test of your skills available offline.