I can give you some of my notes from the previous dev streams. Lore-wise, The Nine have invited us to Kepler, there's some weird space/time stuff going on. Devs have mentioned House of Exile as a major enemy, there will be new Fallen enemy types as they have adapted to Kepler. Devs also mentioned Vex would be there. On story linearity: Devs have said many times they made EoF like a metroidvania, Tyson Green joked about getting sued by Nintendo over it. Typically the genre revolves around skipping past certain areas because you do not have the "upgrade" or traversal tool to access the location. Later on you get the required "upgrade" and backtrack to go down the newly-available route. A note from yeserday's stream: They did mention intending players to have multiple playthroughs, but exactly what that means we don't know. Also during the stream they mentioned that they built Kepler more like a dungeon than a campaign. Abilities: There are 4(?) Abilities, which each have upgrades. Matterspark (arc ball) Rosetta (unknown) Relocator (void portal cannon) and Mattermorph (strand telekinesis). These abilities are the "upgrades" mentioned above, that allow traversal to new areas. Devs have stated these abilities will only be available on Kepler.