Use the Bolt Launcher to get it to work with either RS3 or OSRS. All are Flatpaks available in the Linux Mint repository.
I have been using this for aeons and just had to say - it is life changing improvement to using nxt client on linux. Truly awesome!
Great game. Had issues at first but I appear to have been the cause of the issues I was having getting this to run. It now works fine and i don't know why It did not before.
I've always been a runescape fan boy but i had to install an addition package called libglew to get this to work https://launchpad.net/ubuntu/xenial/amd64/libglew1.10/1.10.0-3 --- just download the deb and try launching after that, worked for me
It seems to lock up and won't install additional dependecies. I also got this Invalid url: 'apt://com.jagex.RuneScape' given, exiting