Limited Interest

The 2021 GMTK Gamejam


Recently was the first Gamejam I participated in, the 2021 Game Maker’s Toolkit gamejam. A gamejam is where participants create a game in a short time frame. Often this time frame is a single weekend over 48 hours, and usually there is some theme to restrict the types of game to submit. These themes may be thematic or may try to dictate the mechanics of the game. The theme for this gamejam was joined together.

Our Game

My brother and I made a game for the Game Boy Advance during these 48 hours using a library created by us. You can play the game, titled “The Hat Chooses the Wizard” on (not my itch account). The source code can be found on the agbrs project account, and the library is

Here is a picture showing the game playing on real hardware.

The Hat Chooses the Wizard playing on a Game Boy Advance on a wooden table.

The web version can have controls rebound by pressing esc.


The game came overall #1202 out of 5801 entries, so we are in the top 20% of all entries, which is nice!


The agb library is a work in progress library for making games for the Game Boy Advance in the Rust programming language. It is very much a work in progress, but it is possible to make games. The idea is to hide as much of the internal implementation of the Game Boy Advance as we can while still being able to use all the interesting tricks available. My brother refers to it as (and I paraphrase somewhat)

You need to know the limitations, but not the hardware

Meaning you don’t need to know which hardware registers to write to and how the bits are packed, but you should know that you can only have 32 different rotation matricies for affine sprites. These should probably be documented as part of the interface, but that’s future work!

Not everything has been implemented yet, and everything that has been implemented is subject to change both large and small.