The open-source city building game for Game Boy Color.
Assembly Pascal Makefile
Latest commit 26e1cbf Jan 16, 2017 @AntonioND Add a margin to the cursor scroll
Instead of scrolling when the cursor reaches the border of the screen,
scroll when there are 4 tiles in between, only reach the border of the
screen when the background can't be scrolled more.

If the cursor is in that extra border and the background is scrolled
back (holding the B button so that the cursor doesn't move), the
cursor will be stuck in that position even if it shouldn't be there,
but it won't advance anymore. Of course, it will work normally in the
other direction.


The open-source city building game for Game Boy Color.


This is a beta version of BitCity. As such, some of the functionality is missing. This is not playable yet, but it's almost there.

It is developed using BGB (, and it's tested on hardware every once in a while.

NOTE: I'm looking for a good pixel artist to help me with the game graphics. If you are interested please contact me at my email (

General to do list:

  • Simulation - Most parts are ready
    • Graphical output (boats, wind power plants?...)
  • Sample cities (compressed?)
  • Music, SFX - Allow to disable it from the options menu
  • Improve graphics
  • Cleanup code and document


  • Start: Open pause menu.
  • Select: Open building select menu.
  • B: If held, fast scroll.


Game made by AntonioND/SkyLyrac (Antonio Niño Díaz)

Email: /




It uses GBT Player, my music player library. It is not needed to install it as it comes with the game code, but it can be found here if you want to use it for your projects:

Tools (for Windows, but they run on Wine):


The Makefile has to be edited to point the RGBDS binaries. Then, open the console and type make rebuild. This should work on Linux, MinGW, Cygwin, etc.


This game is licensed under the GPL v3 license. You may have received the source code of this game along with the ROM file. If not, the source code is freely available at the following address:

Not all source code files are licensed under the GPL v3, though, only the ones with the GPL header are. There other source files are licensed under different terms (for example, GBT Player is licensed under the 2-clause BSD license).

The media files (graphics and music) are licensed under a Creative Commons license (CC BY-SA 4.0).

GPL v3

BitCity - City building game for Game Boy Color.
Copyright (C) 2016 Antonio Nino Diaz (AntonioND/SkyLyrac)

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <>.