PINPULLER

PINPULLER is a real-time freight sorting game set on the hump of a 1950s classification yard at night. A switch engine shoves the train over the crest at a walking pace. You pull the coupling pin to cut cars loose, line the switch ladder to the right track, and squeeze the master retarder so each cut rolls out and couples at a walk.

Every car rolls differently. A loaded tank car runs heavy and barely feels the clamp. An empty boxcar dies early, and a head wind can stop it short of its train. Rain greases the rail and cuts run long. The waybill gives you the destination and the tonnage; the rest you learn by handling cars. The aim band under the speedometer answers one question: let go now, and the cut couples soft.

Scoring follows the Brown system, the demerit ledger real railroads used. Rough joints, crashes, wrong tracks and mishandled DO NOT HUMP cars all earn demerits, and sixty ends your career. Shifts grow from 16 cars on four tracks to 32 cars on eight, and the pace bonus goes to yardmasters who keep several cuts rolling on the hill at once.

Built as one HTML file: a seeded physics model for grade, rolling resistance, wind and clamp force, WebAudio sound synthesized in the browser, and an automated harness that plays full careers headless to prove every consist can be sorted.