Source: Xbox.com

Turn back the clocks and crank-up the action, id Software’s DOOM as of today it's now available for download on the Xbox Live Arcade. The game, which premiered today at X06 in Barcelona, brings legendary DOOM mayhem to gamers, who for the first time ever can relive the classic demon-blasting fragfest in both single-player and 2-4-player co-operative and Deathmatch modes over Xbox Live or splitscreen. DOOM for Xbox Live Arcade is available in most worldwide markets for 800 points and is rated "M" for Mature by the ESRB.
Originally released in 1993, DOOM introduced millions to the terrifying and exhilarating excitement of first-person action. As a lone marine stranded on Mars when a military experiment literally goes to hell, gamers must face off against an army of demons and un-dead marines using the BFG 9000 and an arsenal of classic weapons in order to survive this deadly assault and save mankind from certain extinction. DOOM for Xbox Live Arcade delivers all the era-inspiring action of Ultimate DOOM including all four original episodes in one complete Xbox Live experience.
I hope to see in the near future: Wolfeinstein 3D, Tetris (the original), Paper Boy, Monopoly, and Altered Beast...