I made a game based on what I remember of an old Windows puzzler called FastRing. Sadly I can't find the author name of that old game. I believe it's fairly intuitive to understand if you see a gif:
You select orbs by going in a straight line horizontally or vertically between them and when you link back to the first orb you selected you clear them all. Clear more at once for more points.
Took like two days to make, I like how easy the Playdate SDK is to use.