Change Up!

A cashier arcade game — hand back the fewest-piece change before the register clock beats you.

Change Up! puts you behind the register. Each transaction hands you a price and a wallet of coins and notes; you drag pieces onto the tray, hand over payment, and take back change. You are graded on how close your change is to the mathematically optimal answer, not on speed alone — though the window shortens as you go. Classic is twenty timed transactions; Endless keeps the register open until the clock finally wins.

Gallery

Development notes

The in-game money was decided by law rather than taste. No freely licensed images of Singapore currency exist, and Singapore's Currency Act restricts reproducing it whatever the copyright says, so every coin and note you play with is original art drawn by a script kept in the repo, reviewed and regenerated like any other code. The tool that cropped the mock-up has a guard that refuses anything touching real money. It fired during development, and that crop was redesigned around it.

What's in it

• — Classic (20 timed transactions) and Endless (until the clock wins)
• — Scored on distance from the optimal change, with combo streaks
• — A pressure timer with green/yellow/red windows and a timing bonus
• — Real-world currencies, each with its own coins, notes and change logic
• — Optional global and regional leaderboards; plays fully offline