Ehm, if a it is a Free/Libre Open Source Software, then the *release* will be a tarball with all the data. There is no need to provide any binary. The binaries are created by the distributions and included in the normal distribution package manager. So installing is nothing more than running eg emerge gamename, apt-get install gamename or *whatever* your packagemanager uses. So why care at all about things like a lokiinstaller when using the packagemanager is so much nicer.
I would not like to have to rely to a binary version when using some open source software, since if you have the sources, you can compile it yourself and it will work, so the distributions can include it.
For some closed source software there is of course no real way to directly provide binaries that include in the package manager for all the distributions. That is the only situation I do see for things like a lokiinstaller.
One example for things doing the FLOSS way is wesnoth. You will find it in basically every distribution directly in the package manager and you can get the sources and compile it yourself if you do not want to rely on the binary version of it, or if you don't find the version you want in the package manager.