The Proton Guns are only half of the equation though; after you’ve subdued a ghost you need to toss out one of those containment devices and trap it. I’m guessing the video was just some kind of concept demo of what modern Proton Guns might be like.
The proton gun looks pretty nice in the video above. Ghost Hunter tried to channel the Ghostbusters vibe on the PS2 a few years ago - it was underwhelming.
Somewhere else (slashdot?) was a link to a guy on youtube showing how he beat the old c64 Ghostbusters game, many years later. I remember playing this one back in the day and it was really, really difficult. The video shows how painful it was to get the little pixel ghostbuster between the legs of the jumping Marshmallow man, and then in the comments there’s a line about it being, much much easier to simply run up parallel to the big guy, and then just juke right when he moves right. I never, ever thought of that as a kid, and in retrospect, it seems perfectly simple.
I remember playing the ghostbusters games for the nes. The first one was hard I could never beat the final part. The 2nd one I did manage to beat a few times.