They would look very similar if the design language stayed consistent. With a few changes I postulate below.
I think the videogame packs didn’t really follow the depth of the design language of the 84 packs. I even think the slime blower packs of GB2 didn’t.
The 84 packs were designed with a few key aspects (some of which even long term fans don’t know):
1. The packs were made to accentuate the human body shape and make the wearer look “heroic”:
-The cyclotron on the bottom sticks out from the main plane and is the size it is to accentuate the arch of the back and the glutes.
-The ion arm and the booster/booster frame on the left counter balance the proton wand on the right as both act as extensions to the shoulder width/emphasize the width of the shoulders of the wearer. That’s why on a side view the ion arm and the wand stick out at shoulder height.
-The narrowing of the pack above the clippard is balanced on the left by the ribbon cable and both are meant to accentuate a thin waistline of the wearer. A coke bottle / hourglass shape.
-There is also an overall balance to the non symmetry of the design. It’s for example why the bottom of the ribbon cable (where it connects to the cyclotron) is 180 degrees exactly opposite to the hose by the N filter / exit port. The tightening and upwards curling of the ribbon cable on the left is meant to balance the wand hose on the right.
This was all detailed in the literature (Don Shay Making of Ghostbusters or in one of the documentaries, Crossing the streams or MTMU, I can’t remember.)
2. The packs were designed to look believable Heavy duty and dangerous, hence the black machined and oiled metal color and permanent deep humming noise of their operation. They look serious. But also believable. There is an actual cyclotron (like on a real particle accelerator) that gives the impression of rotation. So thought out operation and not complete fantasy.
3. The packs were designed to look like complicated pieces of machinery Hence all the lights. Complexity and believability comes from placing most of the lights on the actual control surfaces that are manipulated by the wielder (the wand) rather than on the pack. Hence fewer lights on the pack than on the wand.
4. The packs have a depth and mystery to their presence The complexity, seriousness and heavy duty aspect of the packs is also emphasized by depth and mystery: the warning labels. Some are large, simple and obvious (DANGER, Warning, etc.) but some are smaller and feature more text. You get a feeling that you may actually understand a little of how these things work if you could only get close enough to read the text on them. Or pause the video at the right time. Who didn’t do that on the VHS when they were a kid. The mystery is also emphasized by the homogenous black color of all parts. It’s hard to make out details when looking at it.
5. The packs have an element of absurdity and comedy to them The cobbled together look as if they were made at home. Hence all the exposed wires and loose cables. All positioned very specifically however (with legris). Bent and curved to lead the eye and create balance in the overall shape. I.e. the red cable coming down from the HGA and the red cable going up over the clippard are curved the way they are to give breathing space and accentuate the wand that is attached to their right.
These 5 aspects are also balanced amongst themselves. I.e. they look less home made than they look believable and dangerous for example. They look more mysterious than comedic. So there are percentages to each in the design.
That’s why I think the videogame packs (fully modified) were not as strong from a design point. With all the loose cables and clamps hanging everywhere, etc. They didn’t look as heavy duty, sinister and believable. The percentage “home made” and “comedic” was overemphasized at the detriment of things like aesthetics, believability and point 1 above for example.
But to answer your question if the GB’s became a franchise the points above would still be valid (if we are talking GB1/2 proton packs). Just the percentages of each would be different. I think they would look pretty much the same but less home / haphazardly built. So with less loose / exposed cables and perhaps more moulded curved fittings and covers. Perhaps softened very slightly so less sharp edges but losing those would need to be compensated with something else. Perhaps emphasizing point 1. even more. But subtly, maybe more creatively.
To be honest I wouldn’t change a single thing on a GB1 proton pack. I think that’s why J. Reitman just added that one small neon yellow cable by the ribbon cable. To keep it the same but still show it is from GB20. I’m not sure if he used a GB1 ribbon cable or GB2.
PS: actually the two things I would change are:
1. Fixing the direction of the 4 rotating red lights on the cyclotron. I assume they are there to indicate a correct homogenous magnetic field across all 4 quadrants of both the upper and lower dee’s. Clockwise they are not in the direction of the deflector plate (N filter) and the exit port of the cyclotron (the tube going to the wand). Which they would be if they lit up counterclockwise.
2. I would definitely not keep the two white squares on the powercell which were so obviously just rubbed off paint on the Stantz pack in the Sedgewick scene in GB1.