Thought this was about Eve Online which is often jokingly called "spreadsheet in space" because of the data-driven nature of the game.
Weirdly surprised it was about games rendered in Excel.
The first thing that comes to mind when hearing "spreadsheet gaming" is the 4X genre. You could probably create a pretty feature complete 4x game this way.
Cool concept, but the about link appears to not work.
But Excel ain't free, are the games compatible with LibreOffice or any other Excel alternative, that is actually free?