APL game engine is indeed an unusual thing. I don't know much about APL, and never used it (toyed with J back in the days though). I am really interested in the development process and the challenges posed by using APL for that kind of project.

Also, I really appreciate that the ReadMe file doesn't try to sell this project as something more than it actually is - a buggy passion project. Such honesty is, I feel, relatively rare nowadays.

A voxel world is a pretty good sales pitch for APL: the weird-looking part is the notation, not the model.

shameless plug, been working a a voxel editor to create voxels that you could use to decorate a home for a a little creature you have to take care of(a la sims). if anyone has some feedbacks, would be happy to take them!

https://kamio.ai/studio

Also, I really appreciate that the ReadMe file doesn't try to sell this project as something more than it actually is - a buggy passion project. Such honesty is, I feel, relatively rare nowadays.

The author has written two blog posts about their game (the latter is more about APL than the game itself though). You may find these interesting

https://homewithinnowhere.com/posts/2026-03-06-voxel-game.ht...

https://homewithinnowhere.com/posts/2026-05-10-one-line.html

It’s crazy what people make games out of. When I was in a game design university program, one of my classmates used to make complete games (including a JRPG style adventure game) using excel formulas. Not even VBA, which would still be insane… just a bunch of formulas.

Is this what programming has become? We no longer admire the technical achievement itself and we only admire honesty.

Because any technical achievement is easily replicated by AI.

The author has written two blog posts about their game (the latter is more about APL than the game itself though). You may find these interesting

https://homewithinnowhere.com/posts/2026-03-06-voxel-game.ht...

https://homewithinnowhere.com/posts/2026-05-10-one-line.html

Sweet, thank you! Don't know why they didn't post this, it's the bit I'm most interested in.

Oh, nice, thank you!

A voxel world is a pretty good sales pitch for APL: the weird-looking part is the notation, not the model.

https://kamio.ai/studio

Why not make a Show HN? In this thread, it feels a bit misplaced, even though it looks cool.

Sweet, thank you! Don't know why they didn't post this, it's the bit I'm most interested in.

Author here. A video of me presenting this will be uploaded in a week or so, will reply with it here if it’s of use.

Is this what programming has become? We no longer admire the technical achievement itself and we only admire honesty.

Because any technical achievement is easily replicated by AI.

Why not make a Show HN? In this thread, it feels a bit misplaced, even though it looks cool.

Oh, nice, thank you!

Cover

A Voxel Game

This started off as a bet with myself that APL notation would provide an easier way to make a voxel game.

This is highly experimental and buggy.

Controls

W-A-S-D to move
Space to jump
Mouse to move the camera
Q to quit
I to toggle render information
F for fast noclip mode
L to lock and unlock the mouse while in-game
1-5 to select different blocks to place

Requirements

Dyalog APL 20.0
A C Compiler
CMake
Vulkan, DirectX12 or Metal graphics are required. For more information, check here
sdl3, sdl3_ttf and sdl3_image (MacOS with brew)

Instructions

Running on MacOS or Linux

After installing dependencies and cloning, make sure you build and install LSE. e.g.,

cd lse 
mkdir build
cd build
cmake ..
make 
make install

This should install libLSE.dylib on macOS and libLSE.so on Linux in ./libs/ alongside the relevant SDL3 library files.

After that you should be able to run with ./main.apls

Some Linux users may have dyalogscript located in a different directory. If that's the case, the shebang in main.apls should be replaced with the path specified by which dyalogscript

Running on Windows

Compiling everything on Windows is a bit more tricky and is best done with finding the SDL3 dev libraries provided on libsdl3 releases with cmake-gui.

.dlls are provided as a release here which can be placed in a folder ./libs on the directory this repository.

Afterwards, the game can be played through a Dyalog session like so:

]cd <ROOT DIRECTORY>
]link.create # ./avg
Run
state.Play

Compiling Shaders

Source code that gets compiled to different shader formats is in ./shaders/glsl

Shaders come bundled with this repo. However, if you want to modify them, edit the glsl shaders and run ./compile_shaders.sh

Note that this requires the DirectX Shader Compiler, glslc and spirv-cross.

Known Issues

There are significant performance regressions on Windows being worked on.
DirectX12 backend is currently not supported on Windows.
You currently can't play multiple times in the same session.
- Known to syserror 999 !
- There's probably memory leaks somewhere !

Credits

Textures by Madeline Vergani (@RubenVerg)