I will start off first by saying this movie is the most dissapointing movie I have ever seen. The movie Doom is a poor attempt to make a movie loyal to the game. The movie is not like the game at all, the story is changed dramatically. The game is...
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I will start off first by saying this movie is the most dissapointing movie I have ever seen. The movie Doom is a poor attempt to make a movie loyal to the game. The movie is not like the game at all, the story is changed dramatically. The game is about an evil, demented scientist working for The Union Aerospace Corporation, (UAC) it is a fictional military-industrial conglomerate. Their focus is primarily military weaponry, aerospace, bio-research, and other more sinister scientific endeavors, who opens a portal to Hell and allows the demons to escape and invade Mars and the UAC Mars research facility.

The movie however, is a lot different. The basic plot of the movie is quite similar to Aliens in that a small group of space marines go to investigate a deserted facility on another planet, and do battle with vicious creatures until only a few are left who must fight to escape alive.

The following points have been severely criticized by most who have played the Doom games or know about the Doom games. These are believed to contribute to the film's box-office failure and ire of fans:

Why the movie is so dissapointing if you have played the DOOM games:

The origin of the "demons" is no longer Hell (nor is it implied that Hell itself exists), but rather genetic experiments. Many fans thought this was a cop-out and turned the film into "just another zombie movie". The idea of whether a test subject becomes a monster or evolves to a superhuman being (like Grimm) depends on whether he or she is genetically good or evil, and has been criticized as ludicrous.

Iconic weaponry such as the BFG, chaingun and the chainsaw are not used much. The BFG fires only three shots (one of which is off camera), the chaingun fires for about 10 seconds in the movie, and the chainsaw is only used for one scene. A shotgun is only fired three times, and what appears to be a plasma rifle is never fired. The explosion of a BFG round also appeared more like a giant ball of corrosive mucus rather than a massive green explosion, as in the games.

The monsters themselves were inaccurate and/or sparse — it was expected the zombies would be carrying guns, the Imps and Hell Knights would throw balls of energy, and that the other monsters in the game would appear.

The first-person sequence is only five minutes long, despite the original prediction of 3/4 of the movie being first-person. Failure to capture the tense, scary, and foreboding atmosphere of the game Doom 3 (which the movie is supposedly based on) and the run-and-gun action of the original game.

Lead game designer John Romero (Doom, Doom II) did not receive a homage in the movie, as did Carmack and Willits. Many believe this was a deliberate slight directed at Romero and orchestrated by the current management of id Software.

So in conclusion,

If you have played Doom 3, do not watch this movie because you will be greatly dissapointed at this poor attempt to transfer a game into a movie. F' the script writer, F' the movie maker. F' the director. They suck.