I had a play of Aer [official site] last year and, while very early in its development, it was already a really rather attractive and endearing thing. Lots of lovely flying, which is inexplicably rare in gaming. A year on, a new trailer has emerged, and gosh, it's still looking like something rather ace. And hopefully coming out this autumn.
It's so pretty, and you get to fly around in it! I'm sold on that alone, but I'm aware that there's more to it. Inside ancient temples are extended puzzling sequences that provide alternative play from the external swoopy, glidy magic. And until I can play a whole bunch more of it, there's not a lot more to tell you. Just that, cor, I hope it's as good as it looks. Which is "quite good".
A "fall" release is a little ambiguous this far into the year, which means I imagine developers Forgotten Key are keeping options open - we'll be nagging them for preview code soon enough, so they'd better prepare.