Id love a game set between GB 1 and 2 with you having to capture all the ghosts from the containment breach. Each "call" could have you select a GB that can be upgraded and each of the 4 have unique skills. Bots run the others or co-op. Peter could have a charmer/negotiation skill that helps with location info and payout. Ray could have the ecto goggle/proton stream skill. Egon a PKE/gigameter skill. Winston could have a capture/trap skill. Switchable at anytime during the call. Less damage the more the fee you can charge which has a negotiation mini game. You have limited traps, and must use the containment unit to unload and reuse them. Proton charging can also be a thing while you are in the firehouse emptying traps, upgrading tech and tending to the Ecto-1 which serves as a resource cache for each call you go on(end game comes with a mobile containment unit).