No Man's Sky gets regular content updates that add new stuff to the game - graphical updates like new water behaviours for example, new quests, new cosmetics, and new mechanics. Aquarius was the latest update and added fishing and a bunch of fishing related items, quests, and cosmetics.

I've had the game since launch and highly recommend it now. It's very chill, and very pretty. A nice way to unwind after work. When not on a quest, it's a very unguided experience; the trick, I've found, is to set little goals for yourself and then focus on those, one at a time.

The whole message of the game is "the journey is what's important, the destination never existed at all", and the gameplay loop reflects that.

TLDR: They added Fishing

More info here