microjam23

GBA Microjam '23

How to add a new microgame

You can add a new microgame by duplicating the test microgame code files (tmg_test_game.h and tmg_test_game.cpp) and changing the namespace to a new one.

For example, if your new microgame is going to use the xyz namespace, you can duplicate the mentioned code files with xyz_game.h and xyz_game.cpp as filenames.

Remember to change the namespace in the MJ_GAME_LIST_ADD macro too.

Microgame rules

Microgames must follow these rules in order to play along with other microgames, with the animations shown between them and with the pause menu:

• All code used by a microgame should be placed in its own namespace. For example, the test microgame uses the tmg namespace.
• All code and asset files (graphics, music, etc.) used by a microgame should have the code namespace as filename prefix. For example, the test microgame uses tmg_ as filename prefix.
• All microgames must include a text file per asset type indicating the license of all used assets. For example, the test microgame uses tmg_credits.txt as credits filename.
• The start key is used to show and hide the pause menu, so microgames should not use it.
• Butano core functions such as bn::core::update are handled outside of the microgames, so they should not call them.
• All sprites and backgrounds must have a priority greater than 0 (by default, sprites and backgrounds priority is 3).
• The system sprite color palette (used for rendering text, among other things) must not be changed.
• The pumpkin is rendered using a regular background, so microgames can't show two affine backgrounds or four regular backgrounds when the pumpkin is visible (it is visible when a microgame is created and when the mj::game::fade_in and mj::game::fade_out methods are called). However, you can use all available backgrounds when mj::game::play is called.
• Global palette functions like bn::bg_palettes::set_grayscale_intensity and bn::sprite_palettes::set_grayscale_intensity must be avoided, since they're used for the transition between microgames and the pause menu. You can apply palette effects to individual color palettes though.
• SRAM will be handled outside of the microgames, so they should not write it.

Frequently asked questions (FAQ)

How can I disable the test microgame or other microgames?

You can disable a microgame by commenting out the MJ_GAME_LIST_ADD macro call.

Where's the microgame interface documentation?

For now it's in the header file (mj_game.h).