Sudoku Museum
Sudoku that gives you something to do with the solving. Finishing a puzzle funds a dig, digs turn up artifacts, and the artifacts fill a museum you build up over time. It's free.
Two people, one board, at the same time
Share a code and you both land on the same puzzle. Your numbers go in white and theirs in green, so you can see who did what as it happens, and there's a row of reactions for when one of you spots something the other missed. Neither of you needs an account.
What you dig up is real
Over 150 artifacts, and each one carries an actual archaeological note rather than made-up flavour text. The Nefertiti Bust Shard, for instance, comes with where the bust was carved (the sculptor Thutmose's workshop at Amarna, around 1345 BCE), why that city existed at all, and the fact that the full bust was dug up by a German team in 1912. You can read the short version on the placard and expand it if you want the rest.
Digs are themed — Egypt, the deep sea, the Paleolithic — and your museum keeps track of what you've found, what rank you've reached and how long your streak is.
What's in it
Four kinds of sudoku
Classic, Mini, X and Hyper, at five difficulties. The hardest one is called Are You Kidding, which should tell you enough.
A daily puzzle
Everyone gets the same grid on the same day, with a leaderboard running on top.
Over 150 artifacts
Each with a real archaeological note, and the collection is still growing.
Free
Free to play, with ads. See where the money comes from if you want the full picture.