There's a Snap package available for VICE. Unfortunately, I installed it and
the keyboard didn't work for some reason, so I had to compile from source.
Additionally, for C64 emulation, three ROMs need to be in place, as of the
current release, in $HOME/.local/share/vice/C64. These are basic,
chargen and kernal. They can be found here:
http://www.zimmers.net/anonftp/pub/cbm/firmware/computers/c64/
Mind the different versions out there!
Here was the first game I succeeded in getting to run:
https://www.myabandonware.com/game/enchanter-1ns
The "Smart attach" option at the top of the File menu in VICE was fine to get
ENCHANT.D64 to load, though it took a while.
Now to figure out things like GEOS!