IBM PCjr. Exclusive Games - ScubaVenture & Mouser

The IBM PCjr. had eight cartridge games, and of them, two are exclusive to the system.  They don't exist for anything other than a PCjr. and since they came on cartridges, they are not designed to work with any other computer.  These games are ScubaVenture and Mouser.

ScubaVenture and Mouser, both programmed by Nasir Gebelli, are very minimalist, enigmatic games.  As Gebelli only had 8,192 bytes to fit the program in (they use 8KB cartridges), you can understand why they lack anything beyond the minimum necessary to make playable games.

Gebelli himself is something of an enigma, as he began programming games for the Apple II, then he did these PCjr. games and some years later worked for Square in Japan programming Rad Racer, Final Fantasy 1-3 and Secret of Mana.  Thereafter, he quit video games altogether and has not returned to them, despite his obvious talents.

Gebelli's PCjr. games lack polish, which is very unusual as IBM released them and shipped them on expensive cartridges.  ScubaVenture has some very impressive smooth vertical scrolling and supports two player simultaneous play.  Mouser is more of a puzzle game requiring a fair bit of strategy.  Both use the PCjr.'s 160x200x16c mode for colorful low resolution graphics and 3-voice sound.

Common Controls

Press F1 for one player and F2 for two player (That is Fn and 1 or 2 on the PCjr. keyboard).  If left untouched, the programs will enter a demo mode.  Both games use the keyboard by default.  They can use joysticks by pressing the J key on the keyboard.   You can return to the keyboard by pressing the K key on the keyboard.  Press Esc to pause.  Each uses the cursor control keys and the spacebar or the joystick positions and button 1 on the joystick.  When your game is over, you will not be returned to the title screen, so press F1 or F2 to start a new game.

ScubaVenture

Title Screen

The object of ScubaVenture is to collect treasures while swimming to avoid the eel on the bottom of the screen.  If you touch the eel, you are stuck on the bottom of the screen.  Press spacebar/button1 to launch a new diver.  Once your third diver is eaten, the game is over.

Divers, Eel, Score, Fish

You will come across yellow keys, each looking different.  Touch the key to take it, and if you touch another key, you will take that.  Soon you will see some "treasure boxes", and each corresponds to the shape of one key.  If you touch the box with the right key, you will earn points.  You will also earn points if you touch the red fish.  Obstacles include seaweed, seahorses and the yellow "walls" on the sides of the screen.  If you touch one of these obstacles, you will not be able to move forward and must try to find a way to move around or you will be eaten by the eel.  In the one player game, a white diver will randomly swim across the screen and can block you and can take fish.  He can swim through the yellow walls and the eel will not eat him.

Keys and more Keys

Eventually, the tunnel will loop around.  This will allow you to try to obtain a(nother) treasure.  The cavern will loop until you have obtained all the treasures or have lost all your lives.  Once you have obtained all the treasures, you will move onto a different tunnel.  

Treasure Boxes

In the two player game, each player will have three divers and compete on points.  If you are using the keyboard, player one will use the regular keys and player two will use the AWSZ to move Left, Up, Right and Down.  The Tab key will release another diver for player two.  Player one's divers wear a green suit, player two's divers wear a red suit.  When one player loses all of his divers, his diver will turn white and move randomly, just like the one player game.

Obstacles

Starting the game is a bit confusing.  When you press F1 or F2, the title screen will seem to reset itself.  If you keep pressing F1 or F2, the title screen will continue to reset.  Let the music play until the ScubaVenture and NASIR text begin to flash.  When that is finished, the game will start.

More Obstacles

Two Player Mode

Mouser

Title Screen

The object of Mouser is to trap all the mice in each of the nine rooms.  In each room there are walls that you can push clockwise or counterclockwise.  The nine rooms are laid out in a 3x3 arrangement, and you can exit the rooms using the passages indicated.  Each room is laid out in a 9x5 grid.

Starting Out

To trap a mouse, you must box it in on all four sides by walls.  You cannot leave it any space to move.  If you trap a mouse, the cat will eat it when you leave the screen.  The cats are useless otherwise.  If the mouse can move a square, then he isn't trapped.  If one of the sides of the trap is the cat, the mouse will not be eaten when you leave the screen and you can't win the game.  If you trap a mouse, a special sound will be heard and you will receive the points for trapping a mouse.  Sometimes you will enter a screen and the mouse will already be trapped and you earn the points automatically.  The time will also be reset.

I trapped a mouse!

To push a wall clockwise around a pivot, walk into it.  To push a wall counterclockwise, push the spacebar/button 1 as you walk into it.  The wall will turn 90 degrees on the pivot, and you can use the directions to move the walls to where you need them in the room.  If you push one wall onto another, the wall will turn white and the next time you push that wall, one of the walls will be pushed forward in that direction one space.  You cannot push a wall if it would go through a space occupied by a mouse, a cat, the cheese or a wall. Nor can you push a white wall onto a white wall.  Sometimes when pushing a wall, there is some residue of it left behind, enough to block your character from that direction, but the mice can chew their way through it.

The Flashlight

In some rooms, there are pieces of cheese.  If a male (light red) mouse touches the cheese, he will eat it and the cheese will appear elsewhere on the screen.  If a female (light magenta) mouse eats the cheese, it will spawn another male mouse.  Male mice are stupid and walk back and forth in a pattern, but female mice can walk in a much less restricted fashion and are more likely to chase the player.

Dark Rooms and a Female Mouse

Some rooms are dark and require a flashlight to illuminate.  You can find a flashlight in one of the rooms.  The flashlight will only illuminate a circular space around the character, but as you enter and leave the room you can see the full layout for a second.

Two players alternate in trying to clear their rooms.  If the player touches a mouse or runs out of time, he loses a life.  Each player has three lives and the rooms are supposedly randomized every time the system boots the cartridge.  When you start a new game, the same room layouts are used.

Conclusion

ScubaVenture was probably intended for younger players, as the game is much more simple than Mouser. While River Raid probably influenced the game's development, it quickly becomes repetitive in a way that River Raid does not. Each time you complete a section in River Raid, a new section appears.  In ScubaVenture, each time you complete the section, the same section appears until you get all the treasures.

Mouser reminds me of Clu Clu Land for the NES, although Mouser came first.  It is a very frustrating game due to the way the game moves the walls.  You have to think about the direction the wall moves and hope you actually get it to move in the direction you want.  The mice always seem to move in a pattern just one square away from being trapped.  The timer runs down very quickly while you painstakingly try to manipulate the mice into your traps.  Mouser is also buggy in that you can die upon entering a screen where a mouse happens to be in the same place as the entrance.