Thatgamecompany's Sky: Children of the Light has launched on iOS (it will eventually release on Android, Mac, PC and consoles). It's free-to-play. It's also one of the most beautiful things I've seen on a phone, even after just half-an-hour's play.
Players of Journey will immediately feel at home, especially when your avatar pretty much starts off by sliding down a sand dune. Sky does take a lot of ideas from that game, but adds plenty and has a much more pronounced co-op emphasis. As the name might suggest, one of the biggest differences is flight. You soon gain a flight cloak and upgrade it, and using this lets you either float over the usual landscapes or take off and soar over vast expanses of clouds.
The opening is a gentle and enjoyable introduction, before the game introduces other players with whom you solve a simple candle puzzle. After this it opens out for your first real freeform flying experience, one where you're surrounded by other players doing the same thing. After around 15 minutes you'll see the title screen, and then find a hub where, among other things, you can change your character's gear.
Whereas Journey could sometimes be a lonely trek, which made the moments of comradeship all the sweeter, Sky is a much more populated world. Once players are introduced, you'll be seeing them all the time, and immediately you can see that they act as some sort of clue: why's that dude chilling at a cave? Let's check it out. Why're they trying to fly up there? Already I've met a like-minded soul who was happy to stand with me and spam emotes for a full minute before going off to do some co-op exploration.
So far I'm loving Sky, with the only bugbear being a touchscreen dual-stick control method. It works well enough but, like every single example of same, it's finickity at certain moments and you often lose your thumb's 'place' on the screen and have to reset. That aside, I'm keen to explore further and see what this new adventure has in store: I'll report back from the cloudscapes soon.