Doom 3 expansion. Cynical money grab?

This is the first game I have ever cheated virtually all the way through. (I usually cheat after the 10th try on a boss, or once I get bored, I have a hard time _not_ finishing a game, even when it gets tedious... it's an OCD thing I guess.) I picked it up at Target for $19.99 looking for a quick fix. It reminded me of all the things I hated about Doom 3, and made me miss all the things I loved from the previous Dooms. Half of the fun (for me anyway) was goading creatures into fighting each other (stand between a shotgun soldier and an imp and strafe out of the way at the last second... remember that???), or blowing up barrels to take out a hallway of baddies. With the game as cramped as it is, there are few opportunities to do this. I also noticed that the darkness becomes boring and irritating. In the originals, you could see most of the time, and that made the darkness a scary change. With it always dark, you spend the whole game squinting. It captures the effect, but is that fun? It's like sims that are too accurate. Realism != Fun (well, most of the time, at least.)
Anyway, back to cheating. The game starts you off fighting the new creatures, probably to highlight their existence, and it isn't till the middle sections that you get to the stock zombie human worker types. It should have started this way and ramped up. It also allows only one save per level. Mind you, you can save as often as you like, just in the same slot. I prefer to have "backups". (I had about 6 gigs of saves when I was done with Doom 3... it was like this... walk in to room... save... move 5 feet... baddies spawn... kill them... save... move into next room... repeat.)
Jeez... back to cheating... I got sick of the gameplay by the end of the first level, and cheated so I could pick up the story. (Pretty ironic, huh?) Needless to say, there is none. It took about 5 hours just walking from room to room, killing everything. There are only two audio logs, only 3 or 4 cutscenes (boss intros) and three of the bosses look virtually identical, and are defeated using the gravity gun rip off. Even this is poorly implemented. You are forced to use it as a weapon, but you can't see squat while you are holding a huge glowing ball of energy and looking into a tiny dark room.
Enough of this, I'm only rambling on about it, because I'm not going to ask for my 5 hours back, I am going to bitch about them. Buy this game if you really like Doom 3. It is more of the same, sans story and production value.
HOWEVER... I do have to mention that there was an interesting homage to the toxic sewer areas in Doom II. That was momentarily cool... but _only_ momentarily.

Hasn't this expansion been out for ages?