You are the Quantum Clockmaker, trapped in a broken machine where every room lasts exactly 10 seconds.

When the clock runs out, time rewinds and a pale ghost of your previous run appears and repeats it, move for move. Your past selves are the only help you have:

A ghost standing on a pressure plate keeps its door open for you.

A ghost can be a stepping stone: stand on its head to reach ledges that are too high. Stack two of them and you can reach even higher.

Ghosts can carry you while you stand on their heads.

Up to 4 ghosts exist at once. Make a fifth and the oldest one fades away, so plan your loops.

Spikes, pits and closing doors only send you back to the start of the loop; your ghosts stay. Reach the master gear to clear the room.

16 hand-made levels, from a gentle first lesson to a final room that needs all four ghosts working together. Progress, best times and fewest ghosts are saved on the cartridge battery.

How to play

Button	Action
D-pad	Walk left / right
A	Jump (hold for a higher jump, tap for a lower one)
B	Rewind now: keep this run as a ghost (only while standing on the ground)
SELECT	Retry: throw this run away, keep the ghosts you already have
START	Pause: resume, restart the level (removes all ghosts) or go to the level select

Install / run

Download chronosync.gb.

Emulator: open it in BGB 1.6.4, Emulicious or any accurate DMG emulator. Saving works through the normal battery (.sav) file.

Real hardware: copy the file to the SD card of an Everdrive X7 or EZ-Flash and run it on a Game Boy Classic.

Authors & licenses

Game, code, levels, music and sound effects: AriPolar.

Game and source code license: MIT License, Copyright (c) 2026 AriPolar. The full text is in LICENSE, included in the source ZIP.

Tools: the ROM is built with RGBDS (MIT License). The trailer and screenshots were produced with a script that uses PyBoy (LGPL-3.0), Pillow and NumPy; none of them is part of the game or the ZIP.

Fonts and graphics: the 5x7 font, the tiles and the sprites were drawn for this game and are covered by the same MIT License.

Generative AI disclosure: This project used AI (Claude, by Anthropic) for code refactoring and sprite enhancement/upscaling.