The following information pertains primarily to the home computer versions of Ghostbusters, although various aspects of these details pertain to the console versions as well.
Game flow[edit]
The general flow of the game occurs as follows:
- Purchase your car and equipment.
- Accrue money and forestall Gozer.
- Pick a destination on the city map. (Tag ghosts along the way to stall them.)
- Drive to your chosen destination. (Vacuum any of the ghosts you tagged to reset their position.)
- Capture ghosts in a ghost trap
- Return to GBHQ if:
- You are out of empty traps,
- Two men have been slimed, or
- Your proton packs are low on energy
- Once the keymaster and the gatekeeper have entered Zuul (automatic when PKE reaches 9999), you may enter if your current balance exceeds your starting balance.
- Sneak at least two men through the doors past the Stay Puff Marshmallow Man to win the game.
The city map[edit]
The city map screen is where you will spend a majority of your time planning your efforts to capture ghosts and defeat Gozer. On this map, you will see the city laid out in a grid. Two building are marked; the GBHQ which is where you must return to empty traps, clean up slimed men, and recharge your proton packs, and the Zuul building which is where the ghosts are driven to assemble. Throughout the game, up to four ghosts will be visible on the map, traveling towards Zuul from every corner. While the Psycho-Kinetic Energy rises automatically (it starts out rising at 1 point per second but periodically speeds up until it climbs 4 points per second), every time a ghost reach Zuul, it will jump 100 points. For every 1000 points of PKE that build up, the PKE rises faster and the ghosts' speed increases.
Your current location is indicated by the position that the Ghostbusters logo can be found in when the map appears. Moving the cursor in any direction indicates the path that you would like to drive along on the way to your next destination. The more you move your cursor before selecting a location, the further you will drive, and the longer it will take to reach your destination. Any ghosts that you tag with the cursor will become frozen. As you drive along to your destination, the ghosts that you tag will appear on the street. If your vehicle is equipped with a ghost vacuum, you can suck up the ghost as you drive past it, thereby resetting it's position. In order to select a destination, you must not only press the button, but you must also push the joystick towards one block or the other to indicate which side of the street you wish to arrive at.
As the game progresses, some blocks will begin to flash red. This indicates that a call has come in from a customer that a ghost is in the vicinity and needs to be captured. Assuming you arrive in time, the ghost will be floating outside the building and you will initiate a ghost capture. If you are in possession of the P-K Energy Detector, you will also see certain blocks flash pink when your cursor is situated next to them. A pink flash indicates that this block is about to be visited by a ghost, giving you some advanced warning to plan ahead. Failing to catch a ghost will cause the PKE meter to advance 300 points.
Likewise, if you are in possession of a Marshmallow Detector, certain blocks may flash white while the cursor is alongside them. This indicates that at any moment, the ghosts are going to swarm together on that block and form the Stay Puff Marshmallow Man in an effort to flatten the city block. If the ghosts succeed in this, the mayor will subtract $4000 from your bank account to pay for the damage to the city. The only way to thwart such a tragedy is to be in possession of Ghost Bait. The moment that you observe the ghosts swarming to a block other than Zuul, press the B key on the keyboard to activate the Ghost Bait. If you are successful, the ghosts will be drawn toward you instead, and the mayor will award you $2000 for averting disaster. For this reason, Ghost Bait should never be neglected.
Throughout the game, a key symbol and a gate symbol will wander around the streets. These represent the Keymaster and the Gatekeeper. They will move quite randomly, and they may wander past the Zuul block. If they happen to approach it from the proper side, there is a chance that they will settle into place in the block. Once both the Keymaster and the Gatekeeper are locked in place, Gozer will appear whether you are ready or not. The Keymaster and the Gatekeeper will move directly to Zuul once the PKE reaches 9500, and it's possible for them to arrive once PKE reaches 5000. Before then, you can reset their position to the left of the city by driving to any building.
Capturing ghosts[edit]
Once you identify a city block that is under attack by a ghost and drive to it, you will see the ghost floating around over the sidewalk. The ghost, which usually resembles a Slimer, will dart back and forth in the air quite randomly. Your first step is to position the trap on the sidewalk. Anywhere is fine as long as it's someplace that you believe you can contain the ghost over. The center of the screen is usually a safe bet. When you are satisfied with the trap position, press the button to place it on the ground.
Now you must position two Ghostbusters. You will be in control of the man who placed the trap. Move him to the left or to the right. Before you press the button to station him, make sure that he is facing the direction that you wish for him to face. After you press the button once, the second Ghostbuster will arrive. You must do the same and position him as well, once again making sure that he is facing the proper direction before pressing the button. Once both men are situated, and you press the button, they will fire their proton packs. The reason direction is important is because there are two different strategies for capturing ghosts. On the one hand, you can have both ghostbusters face each other, while on the other hand, they can face the same direction. They each have different pros and cons. (Under no circumstances should you try facing the ghostbusters away from one another, as that is the least effective way to attempt a capture).
If the Ghostbusters face the same way, there is no way that you could accidentally cross the streams of the guns. Crossing the streams is an instant failure and not only allows the ghost to escape but the discharge drains your proton packs, meaning you must return to GBHQ to recharge. If the streams are pointed in the same direction, you create a very narrow space for the ghost to move in, and it becomes easier to hold the ghost in position before triggering the trap. However, this method leaves the top wide open for the ghost to slip out of and fly around again, spoiling your efforts.
If the Ghostbusters face one another, you will certainly risk crossing streams if you're not careful about how close you move each man toward the other. As long as you are careful, this method can offer the benefit of creating an inescapable cone in which the ghost will be trapped. While it is free to roam in whatever space you provide it, it will be less likely to escape through the top, making your efforts more likely to succeed.
Once the beams are active, you will press left and right on the joystick to squeeze the ghost in over the trap. Pressing left will move the right man to the left, while pressing right will move the left man to the right. As a result, the two Ghostbusters can only get closer to one another, never farther away. The idea is to squeeze the beams close enough together so that the ghost remains primarily over the trap. Once you feel that the ghost is positioned properly, you will press the button one final time.
As soon as you press the button, the beams will turn off and the trap beam will extend into the air. Once the beams disappear, the ghost is free to roam through the air again, so there is no guarantee that it will remain where you positioned it and that the trap will successfully catch the ghost. You are only increasing the likelihood that it will work. The trap sends a round lasso of energy which climbs up to the sky and then shrinks back down towards the trap. If the ghost touches the lasso at any time, it will become stuck inside, pulled into the trap, and captured. Capture the ghost and you get paid an amount from $300 to $1,000 (mostly depending on your promptness at responding to the scene).
If you take too long, or the trap misses, the ghost will slime one of your men before getting away. It will also get away if you cross streams but you won't get slimed. Its departure will also cause the PKE to jump up 300 points. Since three men ride in the vehicle, and two men are required to trap a ghost, you can only be slimed twice before you are forced to return to GBHQ and get cleaned up. You are also forced to return to GBHQ if your proton packs are drained. This always happens if you cross streams but can also happen if you take too long trying to corral ghosts with your beams. If a ghost manages to slip away from your beams and you can no longer correct the situation, hope is not lost. At the very least, you may simply be able to time the release of the trap so that you capture the ghost in spite of failing to pin him in.
Entering Zuul[edit]
Entering Zuul is only possible when the Keymaster and the Gatekeeper arrive at Zuul. This becomes possible once the PKE reaches 5000, though they won't make a direct effort to reach Zuul until the PKE reaches at least 9500. If the PKE reaches 9999, the ending is forced. Once this occurs, the game will check to see if you have raised more money than you started with. If your current balance does not exceed the balance you had when you started the game, you will fail and the game will be over. If you have accumulated more money than you started out with, you will be granted an opportunity to enter the building.
Unfortunately, entering the building is no simple matter. Positioned in front of the building is one very large Stay Puff Marshmallow Man. He will be bouncing back and forth in front of the entrance in a constant rhythmic pattern. In order to succeed in the game, you must slip at least two out of three men between the Marshmallow Man's legs and into the door of the building. If a Ghostbuster touches any part of the Marshmallow Man (and the collision is very sensitive, based on direct sprite contact), he will go flying away from the door. If this happens twice, you will once again fail to win the game, and it will end.
To sneak past the Marshmallow man, hug the wall, and wait for him to jump away from you. Once he has landed, quickly walk towards the building's doorway.
If you do succeed in slipping two men in behind Marshmallow Man, you will see the ending sequence where the portal is shut by crossing the streams. You will then be awarded a bonus for finishing the game, and given an account number for you to write down so that you can start a new game with all of the funds that you managed to accumulate.