I don't know what in the heck Sony is doing with this but let's go find out.
The Tomorrow Children is like Minecraft meets, I don't know, cold-war era speculative fiction? From the team behind the Pixeljunk series, it makes a lot of dev types steam their glasses, because it leverages a bunch of fancy new graphics tech developments to give a sort of Pixar-like pre-rendered look but in a world you can shape.
These are the things I gather from press releases and what not, but as for what the game itself is: no idea, and the trailer above did not sufficiently illuminate me. For more information, maybe check out Dan's The Tomorrow Children impressions from the second beta.
Or, you know, just go have a go yourself. the free-to-play PS4 game is available right now, so jump on in.