CatchTheLionWars vs Euler's Circuit

This is the first time you can play "Catch the Lion" online against human players. "Catch the Lion" is a very cute chess variant played on a 3x4 board and even a little kid can learn how to play within a minute. However, the game is more profound than meets the eye, so it's also good for those who love to think hard. Also, this game is called "dobutsushogi(doubutsushogi)" in Japan. ■voice nanahira(ななひら) © HEROZ, Inc. © Madoka Kitao Maiko Fujita 2013

Trace every wire in a single stroke, and light up the circuit. Euler's Circuit is a quiet one-stroke (Eulerian circuit) puzzle. Tap or drag from node to node to trace the wires. Wherever there is only one way forward, the current runs on its own — the only thing you ever decide is which way to go at a fork. Designed not to tire you out - Straight runs auto-advance, so you only act where a real choice exists - Dead ends carry no penalty — you simply rewind to the last fork you chose - No lives, no game over, no timers - One set is five circuits: a complete session in about three minutes Clean solutions, not high scores - Three stars per circuit: finish it, finish without a dead end, finish without a hint - "Elegance" multiplies the wire count by Euler's number e (2.718…) for a flawless solve, or √e if you used a hint - New sets open as you complete them, growing larger and branchier - Daily Challenge: the same five circuits for everyone in the world, with a streak calendar - Game Center leaderboards for total stars and today's elegance The mathematics is the game Every circuit is generated so that each node has an even number of wires — by Euler's theorem, a solution always exists. A dead end only means your route stranded an island of wires behind you. The title spiral is an Euler spiral (clothoid). Background particles orbit the unit circle of e^(iθ), colors step around the hue wheel by 1/e, and the soundtrack is synthesized in real time using just intonation (1 : 9/8 : 5/4 : 3/2 : 5/3), with melodies walking the scale in the digits of e. Ads appear only between sets — never while you are tracing — and never in the Daily Challenge. The one-time Premium purchase removes them entirely.