

It’s an alternative shell for Plasma, so theoretically you should be able to do anything in it that you can do in Plasma.
On my Arch box it installed a minimal set of Plasma utilities to support it, which means my setup is still very limited (and I can’t turn off screen lock!), but I haven’t tried if it would change if offered a full Plasma install.
I can most certainly launch Steam, Kodi, Jellyfin etc.
I appreciate that the author expended a whole paragraph making sure we didn’t have any misconceptions about the plot of Face Off with John Travolta