Before I launch into this, let me tell you a small anecdote which puts my opinion in perspective. The earliest video my parents have of me is a Blockbuster Kidprint videotape of me when i was 4, and at one point they ask me what my favorite movie was, to which I gleefully responded "Ghostbusters!". That probably heavily influences my appreciation of this game, but I'm sure many of you share the same sentiment.
All of that being said and taken into account, the first hour of Ghostbusters is worth the price of admission. Unless the game completely u-turns into an abysmal, unplayable mess, I'm incredibly happy with it. The first training mission is so incredibly fun - I had a huge smile on my face the entire time I played it. I can't remember the last time I enjoyed the beginning of a game more (maybe Bioshock?). A couple of quick observations...
The game looks fantastic! Lighting effects really shine on the proton packs, burn marks on the walls, stuff exploding. Very true to original movie.
Voice acting and dialogue is spot on, you can tell the original guys had a blast doing it. *
Difficulty ramps up quick. I'm playing it on the highest difficulty setting and although I was only on the first mission, a couple of ghosts instantly knocked me down (ala Left 4 Dead). The computer controlled teammates are pretty competent so far, and are a big help.
Controls are decent, albeit a little loose. Shooting stuff with the proton packs feels about right, and isn't too simple or too difficult. Switching between the first-person and third-person view is a bit jarring and harsh.
There's a first person view with goggles and a PKE meter that you scan things with. This appears to be a collectible finder and Bioshock-esque camera, whereas you scan enemies for an entry into your Tobin's spirit guide (but of course).
Cutscenes are brilliant, and the pacing is spot on. You're bustin' ghosts in no time right out of the gate, and so far it hasn't stopped. *
Music is straight from the movies. You'll recognize bits and pieces constantly. Interested to see if they keep that going or if they have some original stuff. Hearing the same samples over and over may get a bit old.
In short, if you're a Ghostbusters fan, you have to play this game. It's a bit early to tell if I'd recommend it otherwise, but my overwhelming glee at how FRIGGIN AWESOME IT IS TO BUST GHOSTS is preventing me from thinking straight. Sure, this first impression is biast, but just back off man. I'm a scientist.