Donning the Purple is a 1 – 3 player print and play game about political intrigue in ancient Rome. I have the physical kickstarter game and enjoy it as a solo endeavor.
Avalon Hill’s classic 1962 Waterloo boardgame has been given a facelift by John Cooper, who makes the redone map and counters available as a free download.
Tactical Game X is a modern take on the classic Panzer Leader / Panzer Blitz games, which now are pushing fifty years old. They’re still great, though, and if you love them, you might want to take a look at Tactical Game X.
Cheapass Games offers Renfield, a card game about parts, tools, gravestones and “yummy delicious bugs.”