It looks great, provides a great game world, and is fun, but can be a bit of a chore.
There's not much to say about the gameplay -- it's rote point-and-click, which I'm cool with -- no gimmicky action sequences or minigames. Where it shines, like it should, is in the story and game world. There are a lot of interesting character and story threads with some real depth to them. You're never 100% sure what's going on -- is it a dream, hallucination, parallel world, are people just nuts, what's going on?! There is no voice-over -- all conversation is text -- which I think works well for a game where personalities are so important. A bad voice over in a game can ruin the game world.
Graphics are fantastic, with excellent visual style. It's wireframe 3D with a detailed-but-minimalist style, and great use of lighting (or lack thereof). Animation is very fluid and smooth.
Sound is minimal, but effective -- it adds to and never distracts from the game world.
So why a 7.5? Well, the questing can be a chore. There's a lot of back-tracking, wandering for that one clue or story trigger point. You'll drive your truck around on a maze of roads, you'll walk to distant points to see if there's something you missed, etc. It's never terrible, but I did find myself getting a little bored with the traversing at times when I was stuck for what to do next.
Overall, a very good outing, but with some tedium mixed in.