Dredge

Dredge is a beautiful indie fishing game. The mechanics are pretty simple, but it's just so highly polished that I'd recommend it to anyone. "Something" happened to the old fisherman, so you take his place on the isles and start pottering about in a little boat. Fishing consists of a number of minigames, hitting the button at the right time, and there are a few variations based on fish type. You soon start travelling the seas, helping NPCs and upgrading your boat. There are LOADS of different fish, interesting things to explore, an engaging storyline, relics and mystical powers. I found myself highly engaged throughout.

Pros

The atmosphere is very well done. Lots of hints at not staying out after dark, but nobody who wants to talk about it
The music is excellent and reminds me of Hollow Knight
Time only passes when you move or fish
The NPCs and side quests are well designed
Quests often reward you with books, which you can assign to be read in your spare time. Passing the time through fishing and travelling reads the book, which give minor passive bonuses
Fish are all different shapes, and you have to fit them into your boat around your equipment like Tetris
Boat upgrades, lots of equipment, research for new equipment
The main quest gives you new abilities like speed boosts
Lots of different kinds of fishing spots
Nice art style
A fish encyclopaedia for looking things up
Mutant fish
The boat controls are excellent
Lots of mysteries to explore