The launcher does "works as advertised". However, it also makes each game window appear differently - with the new style header bar, and, rather critically, all mouse input to the main play area fails. Tried this with "Loopy" and "Untangle", both were broken, I'm guessing the rest are too. Tested on Linux Mint 20.1
I downloaded it and all the games went right into it. No more clutter. That's great!!!