So after a few distractions I managed to get the input working. You can click and drag to select coloured tiles. You can’t move to non-adjacent tiles, across colours or back onto a previous tile in the current chain. I managed to get some graphics to show the chain as it is being created:

So now it’s time to move on to the player and their movement using the chain. Looking at the time I don’t think there’s going to be any enemies, and I’m worried about how much time I’ll have to polish the game up.

Oh well. I’m learning a ton about puzzle game development and I’m enjoying the concept of this game so nothing lost and everything gained.