"It popularised concepts of competitive multiplayer and modding that are still core tenets of PC gaming today," adds Hill. "It also popularised shareware, a smart marketing concept that has been reborn in a slightly less flattering light as 'free to play' in recent times.
"Doom really was before its time in pretty much every possible way."
Inevitably for a game this good that you could experience for nothing, Doom proved to be an absolutely astounding hit for id Software, making stars of Carmack and Romero in the gaming world and launching a series that is still one of gaming's most recognisable worlds to this day.
Some of gaming's most important titles owe a debt to Doom: we've already mentioned CoD and Counter-Strike, but let's not forget Battlefield, Half Life, Halo, Gears of War and, of course, id's Quake series.
"Although id Software's own Wolfenstein 3D was arguably the original first-person shooter, its follow-up, Doom, is the seminal game," says Hill.
The Doom series itself is an interesting thing to take a look at as well: Doom 2, was essentially an extension of the original with the same graphics and gameplay, but adding more powerful weapons and made available through retail rather than just shareware and mail-order. Inevitably this was incredibly successful.
Master Levels and Final Doom were really just add-ons and it was a decade later that we got our next significant arrival in the shape of Doom 3, a success in terms of sales and review scores but by no means a classic.
Another decade on and we still haven't got Doom 4, with a major project aborted before it ever arrived,
Now, id Software is a very different place with Romero long gone and Carmack's exit to head up the technology of Oculus Rift leaving any sequel without the two most identifiable men behind the success of the early series.
But, regardless of what is still to come, the impact of Doom in the world of gaming is clear - it is one of the all time greats and, almost without dispute, considered to be one of the most influential titles ever.
Which is more than you can say about the film tie-in with Karl Urban and The Rock.
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