I'm a huge fan of the Doom games. I have played or own every single console release of the game, and know the ins and outs of each version with quite frightening detail - from the music-less Atari Jaguar version and the texture-less floors and ceilings of the SNES port, to the windowed 3DO and 32X versions and the sublime multi-coloured PS1 iteration. I've also played the PC originals to death and more recently the Brutal Doom mod on my mac...yet my personal favourite has got to be Doom 64. You can read about my love for that game here if you so wish, but let's get down to business - you've come to the Dreamcast Junkyard for DC-related prose, not N64 circle-jerking.
Sadly, the Dreamcast never got an official retail port of id Software's genre-defining shooter, which is understandable when you consider the timing of the console's release and lifespan. It was probably too late to put the original games out as an official release, and too early for Doom 3; plus the idea of semi-retro compendiums was quite new at the time and so a re-issue would probably have been derided as unnecessary, and a bit of an insult to those people who had shelled out for a 128-bit system. While retro collections are all the rage these days, back in the early 2000s they simply were not the de rigueur. That said, Doom 3 was years away from release and the game we all know today would have been far too much for the Dreamcast to handle with it's complex vertex shading and texturing techniques - even the original Xbox had to make do with a heavily compromised port of the PC game.
That's not to say the Dreamcast never got in on the Doom action though. Oh no - it got ports of every version you can care to think of thanks to the 'open' nature of the hardware and it's readiness to accept software constructed by talented modders. Of course, when I say the system got ports of the games, what I actually mean is that two programmers with bonafide mad skillz (crt0 and DCGrendel) created DoomDC - a port of the engine which runs the original Doom WAD files. There are also later Doom engine ports for the Dreamcast, such as nxDoom, and that is the one I've had the pleasure of sampling.
I played all of the following using a collection known, funnily enough, as DC Doom Collection - a self booting burnt CD that features a rather basic menu screen and WADs for all of the original games (Doom, Ultimate Doom, Doom II, The Plutonia Experiment and TNT: Evilution, and an added extra - Requiem. I posted a video of Requiem here at the DCJY a few months ago, as I thought it was an interesting fan-made mod where the enemy and weapon sprites are replaced with those from Doom 64, but the level design and visual style retains the dank gloom of the original series (I've posted it again below in case you missed it). Here are some images of the various titles in the series running on Dreamcast:
Of course, due to the fairly elastic nature of the Doom engine, several other popular games from the genre have also made it across to our favourite white joy-block (that's the Dreamcast, folks!) - Hexen and Heretic are two of the most well known. They are both decent games in their own right, but for me they pale in comparison to Doom's bio-mechanical, demonic and frantic shotgun-blasting awesomeness. Granted, the hand-to-hand combat and mystical swords and sorcery gameplay could be considered more tactical due to the need to get in close to the enemies that litter the levels...but for me, unloading a double-barrelled shotgun through the business end into an imp's face is infinitely more satisfying than slashing an ogre with a magic sword. Swings and roundabouts people...whatever the frag that means.
It's probably not surprising that there are various iterations of the Doom engine freely available for the Dreamcast - the game has been ported to pretty much every electrical device with a video output and an microchip inside, and it continues to be a massively popular title with many gamers. The simple 'collect keys and kill stuff' gameplay is fairly timeless and universal in design - indeed the recent Doom 4 reveal at Quakecon 2014 is testament to the series' enduring popularity; and likewise the constant updating of the fantastic Brutal Doom shows just how far the original games can be modded and manipulated.
This is only a little taste of what people are doing with the Doom engine on the Dreamcast. I'm sure there are other projects out there that have either brought or are bringing a multitude of classic FPSs to our beloved undead console, and of course there's the awesome-looking Hypertension: Harmony of Darkness still to come. Naturally, if you know of any other kick-ass Doom-powered Dreamcast shenanigans, let us know in the comments and for further info on all of this stuff, consider checking out the following links: