Sleeeper

Yo-yo tricks. One thumb. Real string physics. Sleeeper is a one-thumb arcade game built around real yo-yo tricks. The yo-yo string is a real verlet-rope physics simulation: it follows your thumb, swings when you whip, and goes taut when the yo-yo sleeps. Hold the screen to lower the yo-yo, release at the right moment to land a trick. Chain tricks together for a rising score multiplier. Game features - Practice Lab: a private coaching dashboard that reads your saved runs and daily trick attempts, then produces a readiness score, weak trick-family diagnosis, recommended drill ladder, family completion map, and copyable practice brief. - Thirty real yo-yo tricks drawn from a century of yo-yo culture: Sleeper, Walk the Dog, Around the World, Trapeze, Brain Twister, Buddha's Revenge, Split the Atom, Kwijibo, and twenty-two more. Each trick has its own motion pattern and timing window. - A genuine verlet-rope string physics simulation. The yo-yo string is a chain of point-masses with stiff distance constraints relaxed twelve times per frame. The string never stretches visibly, it swings like a real rope, and it transfers your thumb's energy to the yo-yo body. - Four play modes. Trick Show walks you through a curated set from beginner to advanced. Endless Flow keeps cueing tricks at rising difficulty until you lose your last life. Daily Chain plays the same twenty-five tricks for every player every UTC day. Practice lets you pick any single trick from the catalog. - Hand-drawn neon-on-black retro-arcade aesthetic. A perspective grid of magenta and cyan lines, an animated crowd silhouette at the bottom of the stage, confetti for perfect lands. - Twenty hand-curated achievements covering trick families, chain milestones, scoring milestones, and a full thirty-trick repertoire badge. - On-device SwiftData persistence for your runs, daily history, and achievement unlocks. - A full Tricks reference with how-to-perform instructions and a one-sentence cultural or historical note on each of the thirty tricks. A Yo-Yo History page with seven real, public-domain entries from the Greek vase circa 500 BCE up through the modern World Yo-Yo Contest. - Procedural synthwave underscore with a slow detuned-saw bass, a sixteenth-note arp, and a kick on every beat. No audio asset files. The score pumps up with your chain and cools down after a miss. - Sound effects synthesized on the audio thread: a soft string-whir for the spin, a crisp snap for a clean land, a filtered crowd-cheer for a perfect. No subscriptions. No advertisements. No in-app purchases. No tracking. No analytics. No account required.