A downloadable game

All future releases / wishlist me on steam:


(I will mail out keys to people that have bought this here when it's ready.)

Small is beautiful. Only 6mb in size (built from scratch in C++/OpenGL and GLSL), this little sandbox game generates gigabytes of procedural city, traffic and world around you as you move (all done in computer memory so no disk space required beyond the tiny install size).

  • Use the in-game editor to define the rules for creating your terrain, grass, rocks, trees, city and traffic
  • Create your own unique look using the wide range of graphical settings from retro-pixelated to film-noir and more
  • Walk and fly around your creation
  • More features (and gameplay) coming soon...
  • Release notes are here.


  • Unzip the zip file
  • Double click the sanctuary.bat to launch


IMPORTANT - UBUNTU 22.+ Users : you'll need to sudo apt install libfuse2 in order to run any AppImage.

  • To add it as a non-steam game launch your Steam Deck in desktop mode
  • Download the AppImage file
  • Right click the file -> Properties -> Permissions -> select the "Is Executable" checkbox
  • Right click the file -> Add to Steam
  • Exit Desktop Mode -> access the game from your steam library's non-steam games and set the steam input control scheme (tap the little game controller icon on the steam game's launch view) to "Keyboard (WASD) and Mouse"


If you have issues with performance then try the following:

  • Reduce the grid size setting -> Settings -> Build Settings -> Grid Settings -> Grid Size (In Tiles)
  • Reduce the tile size setting -> Settings -> Build Settings -> Tile Size (i.e. change from 512 to 256 for instance)
  • Turn off the grass -> Settings -> Build Settings -> Grass Settings (or increase the grass packing / separation distance)
  • Turn off some of the post-processing -> Settings -> Realtime Settings (HINT: SSAO is the most expensive)


(With Keyboard (WASD) and Mouse steam input scheme applied)

  • Configure the city, traffic, terrain, tree, rock etc parameters in the in-game GUI then click "Build" to generate
  • Directional Pad (Arrow Keys / WASD): Forwards | Backwards | Left | Right
  • Left Joystick: If Flying Camera is active then this increases | decreases altitude
  • R2 + Right TrackPad rotates viewpoint
  • Touchscreen: Also rotates viewpoint


If you have any issues then contact me by email: ben@fireflytech.org

Updated 27 days ago
Rated 5.0 out of 5 stars
(1 total ratings)
Tags3D, First-Person, Flight, Game engine, Open World, Procedural Generation, Sandbox, Walking simulator

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Really cool looking project! Looking at your YouTube you seem to be focusing this towards being a racing game yeah? Impressive stuff!

Thanks for the feedback :-) Yes, I think so but still searching and experimenting tbh.

Can't wait to see what you do, will be following this. Racing or not you have a good foundation for something cool for sure.


Thanks :-)