I'm aware of a couple of efforts/approaches of people writing Lua that can run on Playdate and PC via Love2D.
There's Playbit - a framework for creating cross-platform Playdate games
And Donald Hays (aka Dovuro) wrote a sample game that would run as Playdate or Love2D. I have his permission to rework that into a small test game that is sharable (currently it uses copyright ripped assets) "soon".
This is something i want to do with one of my small games and also something we want to look into for Sparrow Solitaire after final version is done.