Linnaeus

Linnaeus, named after the Swedish naturalist who founded modern biological classification, turns taxonomy into a quick daily round. The day's species appears with a photograph and its common name, and below it the first fork of the tree of life: two groups side by side, such as Animalia or Plantae. You pick a branch, and the next fork opens, level by level, six levels in all, until you reach the genus. On 21 October 2026 the species was the Ochre Sea Star, which runs from Animalia through Echinodermata and the sea stars down to Pisaster.

Each choice has a ten-second timer. A correct choice scores points, with extra for speed and for a streak of correct choices, and a clue costs a few points. After each fork both groups show a short description that can be expanded, so a round also teaches what the groups are. The short timer is deliberate: its maker, a philosopher of biology, wanted to keep people from looking the groups up while they play.

The same species goes to everyone each day, and your first game of each day counts on the daily and monthly leaderboards. Earlier days can be played through Previous day and a calendar of previous puzzles; a past day's first game counts toward that day's board, and replays are practice. The game can be played in English, Spanish or Portuguese, has a light and a dark theme, and a share button that copies your result. Ariel Jonathan Roffé built it with Claude Code and launched it on Show HN in October 2026.

It suits anyone who likes nature and science quizzes, and players of tree-of-life games such as Metazooa who want a faster, timed round.