[Alpha] Error: Doom

Alpha. Not all powerups are replaced yet, and most of the monsters are standard ones, but otherwise, go wild. As with the mod this was based on, the best experience comes with Cooperative play. Bring a friend and (literally) knock yourself out.
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More about Error: Doom
This mod is basically a reinterpretation of Serious Sam's Parse Error SE for Doom. Thus, it complements the Serious Sam and Parse Error style of gameplay, which is to say, total uninterrupted insanity in its' purest form.