A fun but lacking game.
The bad: The game only saves at cutscenes it seems and there is no way around it. The game is CPU heavy, so a fast tri/quad core is truly recommended. Your also going to want atleast a 4870 or 260gtx to play at 1080p resolution with some eye candy on. No multiplayer is a definite miss. The game is better suited with a 360 controller vs. keyboard and mouse. Limited installs.
I really like this game. It felt like I was playing in a campy Ghostbuster movie which is an impressive feat really. Definitely worth a weekend of your time if the price is right and highly recommended for Ghostbuster fans. If you have a PS3 or 360, you are probably better off picking it up used or do a weekend rental.