Wolfenstein 3D Classic Platinum, the updated port of id Software's 1992 FPS classic, is currently available as a free download from the App Store.

Playing as the suggestively named B.J. Blazkowicz, a captured US agent who's being held in Castle Wolfenstein, you simply have to escape alive. Yep, that's the objective, folks.

But, it won't be easy.

The Castle is crawling with nasty Nazi guards, vicious attack dogs, and terrifying undead supersoliders. Should you manage to fight your way past these horrors, you'll eventually have to battle robo-Hitler in a climactic boss battle.

All historically accurate, of course.

It may be a little long in the tooth (Wolfenstein celebrates its 20th anniversary this year), but Wolfenstein 3D Classic Platinum is a solid conversion of the game that practically invented the first-person shooter genre.

Whether you have fond memories of this 1992 masterpiece, or you're a curious whippersnapper keen to experience a gaming relic, now's the time to snap up Wolfenstein 3D Classic Platinum.