thanks for pointing this out! Our development team is currently only testing (and officially supporting) 32- or 64-bit Linux Ubuntu 12.04 and 12.10. We however got our demo games (and therefore all other V-Play powered games) running on 13.04 too by adding the following line right after including the third-party libraries in the corresponding project file:
LIBS += -lpng12 -lz -lfontconfig
You may need to install additional packages in case the linker fails:
sudo apt-get install libfontconfig1-dev libpng12-dev
Please keep us updated if this works out for your development environment too. We will then add 13.04 support to our next stable release.