A whole game would be really cool. It also seems like you have a really solid foundation. Well the drag and drop itself is intuitive. Maybe you could just make the colliders of the sockets a bit bigger. What really was "confusing" was the swapping stuff just by hovering, i.e. dragging without dropping. But it was also not that bad. But there is sort of a semantic gap between what you expect from the controlls and what then actually happens.
Yeah 100%. Funny story about the hitbox sizes: they used to all be bigger. It was then I encountered some gamebreaking errors if a rune was hovering over 2 distinct surfaces it could occupy, so the small hitbox is more of a ducttape fix :P. An intended mechanic of the swapping is that you can change the relative position of the runes on the ring by dragging it across to where you want it instead, instead of having to manually move every rune by one spot. I think a better alternative would have been to add a button that shifts all runes by a spot, but that was a programming challenge I did not have time to add to the pile at the time.
Well, even if you would plan on making more slots accessible over time you could just use a linked list (or ring buffer) and then shifting everything by one is actually quiet intuitive. But you would have to be a bit careful with the first and last element.
Cool interaction idea though. I was just playing the game on an chill/asmr level, so I did not really care about min maxing everything. But I could image that if the game gets trickier, that this is really a useful tool to have.