If you liked "The Conduit" you'll surely enjoy the great improvements over the original.
Among the noticeable differences there is the graphical improvement and the high-quality cutscenes. There are some new "Boss battles" which are a nice change of rhythm. There is a new local multiplayer, and in regard of this, the shop system is a welcomed addition; now you can earn money while you play, and exchange it for improvements for your character. Also there are twice as much collectibles, with the addition of the "Objects of the conspiracy".
Apart from all these, we have the same game, and this becomes either the biggest problem or the greatest asset. If you likes the original but wanted more, bigger and better, this is definitely it. If not, you will still have issues with the lack of a good story, character development and such. The game is basically plain: shoot them, follow the path, activate some switches… But if you want some fast-paced action, lots of enemies to shoot, great graphics and multiplayer you shouldn't miss "Conduit 2".
Graphics: 9.0 (well, all the aforementioned)
Gameplay: 8.5 (Highly addictive, great controls)
Sound: 7.5 (Nice gun effects, avarage enviroment sounds)
Entertainment Value: 9.0 (lots of collectibles, local and online multiplayer)
Personal Score: 8.5 (It is not revolutionary, but it IS great)