Online Multiplayer is now out of beta! You can now play with your friends, completing all quests together or just mess around, building a cool world or a large automated factory. You can even ride around in each other's spaceships - although it can be a bumpy ride!
The beta is still available, but no longer up to date - if you tried the beta and want to keep your beta saves, I'd recommend exporting them from the beta version and importing them in the default branch.
Multiplayer works by one player hosting a save, allowing other players to join that save. You do this by hitting Host Save and Join Game in the multiplayer menu. The name at the bottom of the menu determines what character you load the game as (or the name displayed in the games list if you are hosting), and defaults to your steam username. If you only want friends to be able to join the game, uncheck add to joinable games list when selecting a save to host.
The enter key opens the chat, which includes similar commands to the original Aground - including the ability to ban players if needed. Type /help in the chat window to see a list of commands. Hosted games will autosave on the host's computer, and the host can choose to save the world to a specific slot - but players who join the game cannot save - so if they mess up your world, you can ban them and load without saving. There are no restrictions on progression or completing quests for any player. Make sure to communicate with the players if you want to impose house rules!
There may not be a lot of public saves during Early Access - so I recommend setting up a game with someone among your friends or in our discord server! In addition to online multiplayer, this update also includes the following quality of life changes:

• Added surface music track
• Added oxygen generator model
• Oxygen generators no longer animate if they can't produce enough oxygen (but they still light up if powered).
• Right clicking a structure when the fabricator is selected will select that blueprint (if not already selected).
• You can now enrage (enable) and befriend (disable) bots in the com station.
• Placing fuel in the generator will automatically switch the fuel type (if necessary).
• Doors now trap water/oxygen when closed (but, will let both through when open unless a forcefield is placed).
• Ores (when selected on the toolbar) can now be placed back into walls for decoration - be warned, if you place them on an unmineable block, the ore will not be retrievable!
• Worker bots now disable instead of die when they run out of power - you can then dismantle them or recharge them from your batteries.
• Raised worker bot cap to 30.
• Added low oxygen warning sfx.
• Added notification if flight is disabled.
• Increased torpedo damage.
• Removed bright frames from mining animation.