Jet Force Gemini

Jet Force Gemini
Also known as: Star Twins (JP) Developer: Rare Publishers: Rare (US/EU), Nintendo (JP) Platform: Nintendo 64 Released in JP: December 1, 1999 Released in US: October 11, 1999 Released in EU: November 2, 1999 This game has unused areas. This game has unused code. This game has hidden development-related text. This game has unused enemies. This game has unused graphics. This game has unused models. This game has unused cinematics. This game has unused items. This game has unused music. This game has unused sounds. This game has unused text. This game has debugging material. This game has regional differences. This game has revisional differences. This game has anti-piracy features. This game has a prototype article This game has a prerelease article This game has a notes page

One of Rare's lesser known AAA titles for the Nintendo 64, Jet Force Gemini didn't sell particularly well, only about a million copies and has never had a sequel. It was generally met with very solid reviews, despite being criticized for the somewhat clunky camera and stiff controls. It's also pretty gory for a T-rated game.

Sub-Pages

Prototype Info

Prerelease Info

Notes

Unused Levels There’s quite a few of these.

Unused Models

Unused Text

Debug Options

Debug Mode

A debug mode can be enabled by pressing C-Left, C-Right, C-Up, C-Down, R, L, L, R, C-Up, R, C-Down, R, L, C-Right at the title screen. A small box will appear at the bottom right corner of the screen, which displays various information such as the coordinates for player 1, current location, and the amount of free RAM.

Alternately, you can apply the following GameShark code for the same effect:

Version	GameShark Code
USA	810A32D0 0001
Europe	800A3540 0001
Japan	800A3194 0001

Debug Cheats

A total of four debug cheats that were a part of the debug menu in the kiosk version of the game also remain in the final version. The unlimited ammo and unlimited health cheats can also be seen used in the E3 demo version of the game. Apply the following GameShark codes to enable them.

USA version codes:

GameShark Code	Effect
800A5078 0001	All Weapons
800A5074 0001	Unlimited Ammo
800A5070 0001	Unlimited Health
800A5068 0001	Unlock All Levels

EU version codes:

GameShark Code	Effect
800A52F8 0001	All Weapons
800A52F4 0001	Unlimited Ammo
800A52F0 0001	Unlimited Health
800A52E8 0001	Unlock All Levels

Debug Objects

Applying the below GameShark code will display various debug objects in the current map, normally unseen. This will also display red orbs whenever you kill an enemy, display N64 logos in some cutscenes, and render all models during cutscene at once that are normally invisible.

Version	GameShark Code
USA/Japan	8100E138 0000 8100E13A 102D 8100DBA8 0000 8100DBAA 702D
Europe	8100E118 0000 8100E11A 102D 8100DB88 0000 8100DB8A 702D

(Source: Original TCRF research)

Crash Debug Screen

To do: Explain this in detail.

If the game crashes while debug mode is enabled, it will display crash debug screens. A and B change pages, R zooms in and out, C buttons allow you to view different addresses on page 2, and Z views the different memory regions on page 6.

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Unused HiRes Mode

A high resolution mode appeared to have been planned at one point in development, but unfortunately, the code for the mode was never completed. As a result of being incomplete, the mode does not move objects on screen accordingly nor does it work after a level load, resulting in a crash. If you wish to see the results of the high resolution mode yourself, there are GameShark codes below to enable them. Apply the code, then reset your game if you are on a emulator.

LowRes	HiRes

USA codes:

Gameshark Code	Internal Name	Effect
800FF384 0000	Ntsc LowRes	Default 320x237 resolution.
800FF384 0090	Ntsc Widescreen	Default widescreen resolution.
800FF384 00B0	Ntsc MediumRes	446x331 resolution.
800FF384 00F0	Ntsc HiResWide	446x330 widescreen resolution.

(Source: Punk7890 & SubDrag)

Unknown Map

A green and black cube found among the models used on the map screen.

(Source: Original TCRF research)

Unused Graphics

Various level editor related graphics.

A green texture with a red X and "SHOOT ME BIG BOY" written on it. Internally named SecretDoor.

An unused pad with a rocket on it. Internally named BombPad.

(Source: Original TCRF research)

Unused Cutscenes

Use the map modifier code 810A323C ???? to appear in a cutscene from the below sections.

BIGSHIP SEQUENCE

Value: 002D

A cutscene featuring a large ship not seen anywhere else in the game. This cutscene appears to be unfinished as there's no audio and it softlocks the game as soon as it's done playing.

SWAMP CREEKSEQ

Value: 00EB

An unused cutscene in Tawfret which shows a zombie ant slowly walking towards the camera. After a few seconds, the screen goes white.

FOREST DAY LAST SEQUENCEII

Value: 018F

This is essentially the same as the used Goldwood takeoff sequence, except it plays Ichor music at low volume and the SFX is louder. The used version of this is value: 0061.

DOG TUNNELS SEQ

Value: 0199

An unused Mizar's Palace sequence. No player is spawned in this cutscene. The game essentially softlocks.

DOGCHASM SEQ

Value: 019A

An unused Mizar's Palace sequence. No player is spawned in this cutscene. The game essentially softlocks.

Unused Enemies

Dragonfly

An unused dragonfly enemy which can only be found in the unused OTHERS test map. It's currently unknown if this enemy is still functional.

Lava Monster

An unused lava enemy which can only be found in the unused OTHERS test map. It's currently unknown if this enemy is still functional.

Butterfly Bug

A fully-functional unused drone enemy which can only be found in the unused GALAXIANS test map.

Horn Galaxian

Another fully-functional unused drone enemy found in the GALAXIANS test map.

Red Ant

An unused flying red ant only found in the unused ANT TYPES test map. It appears to be fully functional as it will shoot you if you get too close. Since the map it appears in has no AI programming, it won't move around.

Spanner Hand

A large robotic enemy which can only be found in the unused BIG BADDIES test map. When you're near the enemy, it'll fire a laser which harms you. Oddly, it makes a rooster crowing sound which was most likely just a placeholder.

Unused Weapon

An unused weapon can be found left within the game. The projectile consists of one green bullet, however, when hitting a wall it will branch off into three extra projectiles. This goes on for about four seconds until it disappears. When a direct initial shot hits an ant, they will explode. The gun has no special icon or sound. The sound is that of a pistol shot, and the icon is of the Grenade weapon. Apply the following GameShark codes to have the weapon:

Add to Juno's Inventory (must have at least 2 weapons first):

Version	GameShark code
USA	811E6214 0064 811E61EC FFFF
Kiosk	811E36F4 0064 811E36CC FFFF

Or replace Juno's current weapon with it:

Version	GameShark code
USA	811E6214 0064 801E6252 000F
Kiosk	811E36F4 0064 801E3732 000F

(Source: Original TCRF research)

Unused Sounds

Instrument Samples

Two drum type instruments which were used in GoldenEye and Perfect Dark can be heard here.

An unused jet pack sound which was only used in Blast Corps can be heard here.

(Source: Original TCRF research)

Rooster

A rooster crowing. This sound is only used by an unused enemy.

Unused Music

Three unused songs remain in the game.

You can apply the following GameShark code to listen to them in-game.

Version	GameShark code
USA	800A0698 00??
EU	800A0908 00??

Where "??" should equal one of the following values:

36 Unused song 1
3F Unused song 2
2C Unused song 3

The third song was originally value 4F in the kiosk demo version of this game. The first two unused songs remain the same.

Unused Song 1

Unused Song 2

Unused Song 3

Unused song 3 sounds like it might have been used in Tawfret at one point.

(Source: Original TCRF research)

Out Of Bounds Boxes

In the second area of Cerulean, there are a couple of small blue boxes placed just outside of the map. It's possible to see these in-game by clipping the camera through the wall. These boxes don't appear anywhere else in the game.

(Source: [1])

Anti Piracy

On bootup, the game checks for the correct CIC lockout chip. NTSC copies check for a CIC-NUS-6105 and PAL copies check for a CIC-NUS-7105. This check is done by using the challenge-response feature of the 6105/7105. If the check fails, the game will enable a couple of anti-piracy features:

You won't be able to use any of your weapons including the fish food. Pressing Z will make your character hold their weapon up, but they won't fire anything which makes it impossible to get past the first life force door in Goldwood as it requires you to shoot down three enemies.

The second anti-piracy feature is that you won't be able to run at full speed anymore, only a very slow walk. This feature only affects Juno though as Vela and Lupus are still able to run at full speed.

Most backup devices usually piggyback off of another cartridge containing a 6102 or 7101 lockout chip which activates the anti piracy function.

Internal Filename Oddities

• Amusingly, the boss in Tawfret is internally named FatBob.
• The Shocker weapon is internally named ShrinkBeam suggesting that at one point during development it may have shrunk enemies instead of electrocuting them.
• King Jeff, Magnus, and Midge are internally named MrHints1, MrHints2, and MrHints3 respectively.
• Some objects are named after developers.
  • The large alien that appears in Eschebone and it's tongue are named stevegrub and stevetung respectively.
  • The sliding doors found throughout SS Anubis are named bryan_door.
• The Spacestation and Walkway levels are internally named Steve Sewer and Lee Walkway respectively.
• One of the rooms in Ichor is internally named MilitaryBase JetPac Room even though you can't use the jet pack in this particular room.

(Source: Original TCRF research)

Regional Differences

North America/Europe	Japan

• The English font is different and larger in the Japanese version.

North America/Europe	Japan

• The game's logo was changed in the Japanese version.

North America/Europe	Japan

• The debug display is less informative in the Japanese version; however, the code to enable it remains the same.

North America/Europe	Japan

• The button icons have letters on them in the Japanese version.

North America/Europe	Japan

• The SFX icon in the options menu was changed to SE in the Japanese version.

Other Differences

North America/Europe	Japan

• The American and European versions allow up to 16 letters for a save file name, while the Japanese version allows only up to 8 letters.
  • In the international versions, pressing B will always exit the name entry keyboard. This was changed in the Japanese version so that B acts as backspace if there are any characters currently typed in.

North America/Europe	Japan

• The Tribal's blood is red in the American and European versions and blue in the Japanese version.
• Certain cutscenes can now be skipped in the Japanese version, such as the cutscenes for when the characters' ship descends on a planet.
• The Japanese version no longer auto saves after getting a new record in a level.

North America/Europe	Japan

• The Spacestation level was renamed to UFO.
  • The level names were also moved from the right side to below and the extra numbers were removed.

North America/Europe	Japan

• The Japanese version displays seconds on the game time in the file select screen.

North America/Europe	Japan

• The Japanese version no longer displays milliseconds in the game timer upon completing a level.
• When low on health, the indicator will flash in the Japanese version.
• In the international versions, enemy heads can be collected to unlock cheats. Enemy heads can't be collected in the Japanese version, so the first two cheats are unlocked at the start. The third cheat, ants as pants, was removed.

North America/Europe	Japan

• Each region in a level has a unique name in the international version. In the Japanese version, the regions are simply named Zone 1, 2, 3, etc.

Rare Replay Differences

To do: Check for more differences.

• The Nintendo logo is no longer displayed on startup.
• All N64 controller prompts were replaced with Xbox controller prompts.
• The noise effect that appears when Lupus uses the night vision goggles is no longer present.
• All mentions of Nintendo were removed from the credits.