Is there an ending?

[knifebladepresents]

Just got this game and I was wondering, is there an official ending? Is there any main mission you can complete?

[Virtual_Wolfy]

There's no official end to the game. You can set yourself some goals, like gathering all story and event signals, seeing all Events or fully upgrading your systems but the game is being updated quite frequently with new stuff to look forward to.
To my knowledge, no official ending is planned for and won't be for as long as the game is still going to being worked on.