It's soooo bad!! It would be a fun game, and I would judge it differently, if it wasn't called "Perfect Dark", but unfortunately, with a brand name like that you have to expect this game to at least reach the standard of its predecessor. I'm guessing since it's been so long since Perfect Dark that all of the original creators/writers/animators are probably in retirement homes or on to other things, and it definitely told.
Obviously the graphics are better, but the faces look sooo cartoony. There's also a body armor that the enemies wear that you can literally shoot off, it just looks stupid. The level design is nothing special and very repetitive, you are never blown away, and it's damn near impossible to see your enemies in the jungle level. The objectives are stupid, trying to rip off (or borrow from, if you actually allow yourself to consider this as a sequel or prequel or whatever) from the original but failing miserably. The vehicles are also quite silly. In fact, the entire game is silly, I don't think there's any blood and it may be a PG game. Which may also explain many of the shortcomings.
The voice acting is the worst I've ever heard, the dialogue is even worse, and the story is just crap. There aren't as many guns as there were in the first one, and the new gadgets are stupid (locktopus? what the hell?!) Enemies are still stupid (they were fairly dumb in the original but that was ages ago, they were geniuses considering the AI standards back then) and say stupid things, but they were funny in the original ("you *****! KILL HERRRR"- it was funny a decade ago, trust me).
The music of the first game was terrific, with little noises in the background that really made you feel like you were heading into an alien cave (deep sea) or doing some corporate espionage or whatever. This game's music is completely unremarkable. And that's the best I can say about this game in general.
Basically the graphics are OK, but the rest of the game is either unnoteworthy or bad. And that's not comparing it to the other Perfect Dark, which it doesn't deserve to be affiliated with. I used to love Rare, with Donkey Kong, GoldenEye, Perfect Dark, Conkers etc. but this is unforgiveable crapness.