Still throwing an error on the Playdate website.
Update your pdxinfo file to just this:
name=JimInTheBox author=Lurgypai description=A game to show your friends how much fun the Playdate is! bundleID=com.lurgypai.jiminthebox version=1.0 imagePath=images/assets
I was able to get it to side load by making that change.
However when running the game on my device, I see an error message "Update Needed - The game must be updated to run on the current system version"