off-orbit-gb

Off Orbit reborn for the original Nintendo Gameboy. An asteroids style game where firing the ship's weapon also moves you in the opposite direction.

Development Prerequisites

This game is built on Windows with GBDK or gbdk-n. gbdk-n seems to make a build that runs smoother.

This tutorial series created by GamingMonsters is a good learning resource for GBDK/gbdk-n.

gbdk-n

1. Install SDCC 3.8.0 with a prebuilt installer (newer versions did not work for me)
2. Install gbdk-n at the root of a drive (i.e. D:\gbdk-n)
3. Run make in your gbdk-n folder to build it
4. Ensure make.bat has the correct path to the gbdk-n folder
5. Ensure SDCC is in your path

GBDK

1. Extract the gbdk zip at the root of a drive (i.e. D:\gbdk)
2. Ensure make.bat has the correct path to the gbdk-n folder

Other Tools

• BGB emulator for testing the built off-orbit.gb file
• GBTD for creating tiles and exporting the data to .c files
• GBMB for creating tilemaps and exporting them to .c files
• OpenMPT for creating the music in raw/music.mod
• Pyxel Edit to edit composed sprites easier (split pasted into GBTD)

Music

Run the following to recreate the src/music.c file after making changes to raw/music.mod:

$ make music

This runs mod2gbt and removes the #pragma bank=2 line from the generated file so it doesn't use banking (breaks the build).

The gbt_player* files in this repo are modified to disable banking (https://gbdev.gg8.se/forums/viewtopic.php?id=466), since SDCC doesn't support it and this game is made for a 32KB cart which doesn't switch memory banks.

Building

Run this to build dist/off-orbit.gb with SDCC and gbdk-n:

$ make

Run this to build dist/off-orbit-lcc.gb with GBDK:

$ make lcc

Remove the temporary build files with the following:

$ make clean

Drag a .gb file into BGB to test it out.