The current method to create a cross-Linux install package for the desktop client is getting rather old. Meanwhile, there are new package formats that make multi-distro packages very easy and come with an application store. Snap packages are one of these new formats and so I've created a snap package for the Linux Client. Updates are automatic and there are four channels to use which enable stable and beta versions etc. I would very much like people to give it a try and let me know what you think and if you have any problems.
The store is https://snapcraft.io/store where you can search and find the new package, or go straight to it here https://snapcraft.io/eternallands. You can also find the package in the Ubuntu store. Once installed you will have a new desktop launcher icon labelled "Eternal Lands (snap)". The launcher defaults to the main server but you can choose test or pk by right-clicking the icon. You can also run from the command line using "eternallands.client" and specify any configuration you wish as a parameter. The package includes the data, sound and music files.
Things to note:
One known issue is that opening URLs does not currently work, (this silently fails) but I'm investigating this and will update when its fixed.
The personal configuration files do not get stored in the normal place $HOME/.elc but in $HOME/snap/eternallands/current/.elc (actually a link to $HOME/snap/eternallands/common/config) . There does not appear to be a way to use the normal location this so you will have a clean configuration. You could copy existing files over as the data directory is automatically fixed at run-time. On the up side, this will not interfere with any existing install.
If you remove the snap package, all user files for the package are also removed so keep this in mind and back-up if you need to keep them. There does not appear to be a way to prevent this. The snap developers are currently working on a snapshot facility that will avoid this and, in addition, enable you to make backup copies of you configuration files too.
The other, competing cross-distro format is https://flatpak.org so I intend to look at that too I have created one of those too.