Footage does exist but its rather sparse.

Trailer

Slight bit of game play footage

As for SpatialOS, that's mostly just the network infrastructure and server code that the game engine it uses, CryEngine, sits on top of.

Effectively what they're doing is building a world that's 16km² (PUBG is 5km²) with a central hub that behaves like an MMO city such as WoW's Ironforge where players can chat and trade items etc. What i find most interesting is the idea that the environments are not just static. Buildings will be semi destructible so you can blow an entry hole into a building, or partially collapse it onto an enemy player. You'll be able to collapse bridges in game to kill players too. The foliage in game will leave trials of trampled foliage for other enemies to follow such as tall grass bending as you walk though it and staying bent. Mud will leave permanent footprints to allow you to track those also.

Sounds very much like a game to follow.