Play locally via a network with up to 4 players through the single player campaign. You can play on the internet using various 3rd party utilities. Tons of versions available as well.
The Ultimate DOOM is the classic DOOM but with an additional fourth episode "Thy Flesh Consumed".
This page contains co-op info for The Ultimate DOOM on the PC. All information about The Ultimate DOOM was correct at the time of posting. Information is subject to change. If you see any errors please email us.