Hello,

I just wanted to play Democracy 3 on Ubuntu 22.04.05 but encountered the following error:

./Democracy3.bin.x86_64: error while loading shared libraries: libpng12.so.0: cannot open shared object file: No such file or directory

I thought it might interest you that in order to make the game run again it is only necessary to add the libpng12.so.0 file to the lib64 path of the game.
I guess the same goes for the i386 version of the library - then of course it would have to be put in the lib path of the game.

The library can be found here: launchpad.net/ubuntu/+source/libpng

I used the version you can find here: launchpad.net/ubuntu/+source/libpng/1.2.54-1ubuntu1.1

For amd64 you find the .deb file here: launchpad.net/~ubuntu-security/+archive/ubuntu/ppa/+build/15108504
Direct download would be launchpad.net/~ubuntu-security/+archive/ubuntu/ppa/+build/15108504/+files/libpng12-0_1.2.54-1ubuntu1.1_amd64.d eb

For i386 you find the .deb file here: launchpad.net/~ubuntu-security/+archive/ubuntu/ppa/+build/15108507
Direct download would be launchpad.net/~ubuntu-security/+archive/ubuntu/ppa/+build/15108507/+files/libpng12-0_1.2.54-1ubuntu1.1_i386.de b

After extracting the files of the .deb you should see a file named data.tar.xz
After extracting the files of data.tar.xz you will find a lib path and following it you should see two files: libpng12.so.0.54.0 and libpng12.so.0. Since libpng12.so.0 is only a link to libpng12.so.0.54.0 you should delete the libpng12.so.0 file and rename the libpng12.so.0.54.0 file to libpng12.so.0 - this one goes to the game directory.
I would have attached the files but unfortunately I can't upload ZIP-files here.

Hope this may help other users, too :-)