It's a simple game, you fish in a simple multiplayer environment. You can sell the fish for in-game currency, and use that to buy fishing upgrades, cosmetics to decorate your Animal Crossing style character, or other silly gimmicks. It's less about the fishing and more about just hanging out in a space with friends, however there is more than enough content to play alone (And a solo mode when creating a lobby).
I've got a few hours in already, up to level 21 as of writing this

