You've been watching too much YGO or YGOAS.
...IN AMERICA!
Okay, this is what I've always wanted to play in the GB universe:
You have a 3-D hotel with at least fifteen floors and about 25 rooms per floor. You're looking at it from a 3/4 down angle and the camera can be rotated 360 degrees around with the L1 and L2 buttons. There is always one floor highlighted in yellow, and the highlighted yellow floor can be swapped with the R1 and R2 buttons (up and down). All floors above the highlighted one are 80% see-through. You also have a room always highlighted in pink, and that highlight can be moved with the D-pad. Ghosts appear as symbols (even if they are in a see-through room or buried under visible floors) and you can always see them and where they are.
The Ghost Busters arrive at the hotel and you have to direct them to specific rooms. There are rules governing how different ghosts have to be captured, including how much beam energy is required (gather more GhostBusters or get individualized upgrades for each character) or what type of energy, whether or not they can even SEE the ghosts (requiring equipment or the elimination of artifacts that protect the ghosts) and what-not.
With a room highlighted in pink, pressing X, O, square or triangle will summon the corresponding GhostBuster to that room. Furthermore, pushing Select on a room will zoom you in on that room and you can then take more detailed control over the action inside.
The trick is that the ghosts are actively trying to take over the hotel's structure, and every room they own becomes twisted or otherwise tainted and can then start to spawn new ghosts as they convert the hotel into a portal to the realm of the dead. Some of the summons will be slower but meaner, some fast and easy to kill but prolific. Each GhostBuster also has a limit to the number of Traps they can carry, and how much protoplasm each can contain (upgradable), so if you've used up all of Egon's Trapspace and he's the only GB with fire element energy, you'd better run him back to the car and dump his traps as fast as you can while fighting the growing infection of ghosts with the other three as best you can.
The game would basically be a GhostBusters Sim with RPG elements, because between each level you'd be able to upgrade the GhostBusters with unlockables and such.
