LIB "libpng12.so.0" is missing on newer linux systems. Installation OK, but the game won't start properly. To fix this on debian based systems, do: open shell ~# mkdir temp123 ~# cd temp123 ~# wget http://ftp.ebian.org/debian/pool/main/libp/libpng/libpng12-0_1.2.50-2+deb8u3_amd64.deb ~# dpkg-deb -x libpng12-0_1.2.50-2+deb8u3_amd64.deb . ~# cp lib/x86_64-linux-gnu/libpng12.so.0.50.0 "$HOME/GOG Games/Deponia 4 Doomsday/game/libs64/libpng12.so.0" ~# cd .. ~# rm -rf temp123