This is the shorter version of the TV commerical – here’s Ryan LeClair’s description of the longer commercial running on Cartoon Network;
it starts with the Ectomobile from the game (Ecto-1B) rolling up next to a house. While someone with a “green glowing arm” (Slimer) sits in a chair with his hand on the remote. He’s watching the ad of the three GB’s from the start of the video game on his TV. The door busts open, and we see a silhouete of a GB w/ a pack. Probably the player’s character. He pulls his Proton Gun, a few shots of the game ensues and Slimer fly’s at the screen, sliming it, revealing the GB game cover art for the PC, 360 and PS3.
[UPDATE] The longer video is on YouTube now.
Big thanks to Matthew for both video links!