A Short Hike was one of the hidden gems of PC Gaming in 2019, a relaxing indie about a bird going on a walk/glide/swim around a nice big park to find all kinds of neat, pretty things as they go. A super-chilled exploration and adventure game with a few puzzles to figure out and all kinds of collectables to amass.
Yes, this might sound like a joke, but it ain't. It allows you to see what other players are doing around Hawk Peak. It's a bit of a Dark Souls thing going on, I guess: They're like phantoms in separate worlds. The state of the island isn't synced between players, so NPCs, Items, and such are different on everyone's screen. Only the players are the same.
It's not going to be supported forever, as it's just an experiment on the part of developer Adam Robinson-Yu, so I recommend checking it out while it's around and the servers are up during this limited period. That said, you could host your own server in the future for whatever reason, but that'll take some technical knowhow.
You can find A Short Hike 99 on itch.io, along with instructions on how to install it if you're using itch, GOG, or Epic. If you're on Steam, you can use the Betas function to switch to a branch called "ashorthike99_mod." To do that, right click on the game, go to "Properties," click "Betas" on the right hand side, and use the drop down menu to select the mod.