Islands of Insight on Steam
store.steampowered.com
Seek out and solve 10,000+ puzzles at your own pace across this sublime shared-world puzzle game.

I’d always been on the fence, always online requirement isn’t great for my unstable Internet, but when I saw it was free today, I’ll roll the dice on my Internet being steady enough to play it.

I hope it doesn’t signal trouble from the developers, but it’s a free (previously 30$) game if you grab it in the next 23 hours