A terrible game thats only saved by its outstanding use of technology.
The story is so shallow you dont even have a name. You are a generic marine. The bad guy? Malcolm Betruger, a wacko scientist (omg!) who wants to bring Hell on Mars (and Earth, if he cans) without any plausible reason whatsoever. Thats the excuse to have you blasting demons for 17 hours in dark, tight corridors while finding keys (oh, sorry. They are PDAs now), suffering cheap scare after another.
Most people will say this simplicity is a tribute to the old Doom... But thats just lame excuse to hide the fact that gameplay-wise, Id screwed up badly with this game. There are no real narrative gimmicks, the characters are extremely unbelievable, and the circumstances are a constant thorn in the side of the story. The fact that no weapon has an alternate fire mode, makes this game the incredibly standard parade of "Pistol-shotgun-machine gun" which have a lame sound that contrasts heavily with the ambiental perfection that surrounds you.
This leads to the good points. The shadow and light technology is outstanding, and the use of bumpmaps, while sometimes excessive, guarantee a high level of graphic quality. the sound is well made (except for those weapons... jeez, air guns anyone?) and the ambient sounds are incredibly varied. The bestiary is well rendered, though limited (no more than 12 creeps) and the gore is pleasing.
However, thats it. This game is just pure graphic engine. The "game" is a repetitive exercis of killing imps sloowly, without any of the fun that the original Doom had. The ending is absurd, and brings no closure to an already limping story.
A less-than-mediocre game, with great graphics, but nothing else.