Here's a brief rundown:
- A new story. the lore of Atlas continues and the path has been reworked some. The NPCs you could have in your home have changed dialogue to fit the new story. Apparently, there's 30 hours worth of story content here. The long-rumored fourth race is here!
- The galaxy has been redone again. Your home planet may look completely different now. The variety has been significantly increased.
- They've added economy, wealth, and conflict ratings to each system, and those ratings affect what you can find.
- You can now find crashed freighters on planets and loot them.
- You can manipulate terrain with a multitool upgrade.
- There's a mission board in every galaxy with procedural missions.
- The amount of items you can craft and find have increased dramatically.
- The visor looks very different, and scanning can help you find rare items.
- The menu UI has been overhauled, to accommodate a new ship inventory system (you now have separate areas for equipment and cargo) and a more in-depth reputation system.
- Portals are now functional! You can input the coordinates of planets to transport to them. Which helps with...
- Multiplayer! In a sense. "Glitches in the simulation" are causing fragments of other participants to show through, and voip works within a certain radius. Basically, it's the Fable 2 take on multiplayer where everyone else is a floating orb. BUT it's the start of more to come, and still neat.
- You now have the ability to fly low to the ground instead of hitting an invisible barrier far above the surface.
- There are new ship models, some of which are only available in high-wealth systems.
- Tons, tons more. But those are the big ones.
Full patch notes with screenshots here: http://nomanssky.com/atlas-rises-update/
And just a reminder, No Man's Sky is $25 on PSN, GOG, Steam, and Humble right now so if you don't have it, now's a good time to get it!