I have learned one very important thing from Loop: all games should have an ambient rain slider in their sound options. I'll be contacting our John to get it on his next list. It is that most tranquil, serene of things and matches this simple puzzle game marvellously. You move hexagonal pieces around until lines of colour match up, flowing together in the titular loop. Developer John Cullen has deliberately included no elements that lead to a fail state or frustration, so you can go forever until you work each puzzle out. It's not finished yet but you can play a demo of the first six levels.
It is properly relaxing, every piece of it meditative and calming. Mousing over pieces produces a satisfying plop, and the music is on a long, uninterrupted cycle. Clicking the final bit into place and watching the puzzle expand slightly as a reward is unbelievably satisfying for something so simple. It quickly grows more complicated than simple forms like the one above, with rotating pieces and ones with multiple colours on them. There's strategy to it; I started prioritising a single colour using an obvious corner piece as a starting point. These can only go in so many places, usually around the edges, due to the interconnectivity elsewhere.
I've chosen not to embed the trailer because it shows solutions to around half the puzzles. Just go play the demo.
John's running a Kickstarter but only for £250 (it's £10 short right now), to pay for licenses and the Steam Greenlight fee. Pledging £3 would get you the finished game on Windows, Mac, and Linux.