RPS Asks: What Do you Want From Doom 4?

So, if the (reportedly false) rumours are to be believed (update: and apparently they're not. Hooray!), the future of Doom 4 might be in doubt. Which raises a question: what do we want from a fourth Doom game anyway? Should the next Doom game keep it old skool with a key-collecting run-and-gun? Or should it up updated to compete with the contemporary manshoots? Do we still want demons on Mars? And should it showcase the next generation of graphics, or do something new with the way shooters work? If you were in charge, what would you do?

Personally I quite like the idea of re-releasing a blow-by-blow remake the original game in an astonishing modern engine, with the only gameplay concessions to modern design being mouse-look and so on. Failing that, a single-button iPhone game, like Canabalt with cacodemons. (Not really. Likely.)