There's a ton of things I loved about this game.
* The full voice cast of the four guys, plus more.
* The music.
* The references to the movies and animated series. Slimer!
* The incredibly well-written story.
* The generally solid overall voice acting. Dan pours his heart into playing Ray Stanz again. Ernie Hudson is solid too.
* Solid level design. Each level is diverse and interesting with a lot of stuff to see and do.
* Genuine laugh out loud moments.
* The HUD design. Not obvious onscreen, but still tells you everything you need to know.
* Interacting alongside the four guys makes you feel like you're part of the team. Who cares if “Rookie” doesn't have a name? It's easier for me to pretend I'm with them.
* The slime blower is addictive. I love sticking objects to the ceiling.
* The big one: Ghostbusting. You always expect the first encounter to be fun, exciting and new before slipping into routine. Many, many busts later, I am still getting excited to trap ghosts. You have to work to catch a ghost, and there's still a feeling of accomplishment after each one. PKE tracking is just as interesting and fun. I honestly haven't been this excited since I was 8 years old.
* I was surprised that the game has some genuinely scary and creepy parts. There have been a few parts that have made me jump, or really fill me with a sense of “oh crap” dread, especially building up to boss ghosts.
* Captures the feel of the movie. Holy crap, does it ever. I hope this becomes part of “canon”, because frankly, it deserves to be.
Overall, this game has been well worth the wait, and is wonderful. Easily my “Game of the Year” for this year.