Save File 0 is a first-person horror game running on a real Game Boy Color

Ki10 Games revealed its native GBC raycaster on Halloween. Two saves share one office, one of them is wrong, and the thing inside it cannot be killed.

AI-drafted from 2 sources. This story was written with AI from the outside reporting listed under Sources, and checked by automated tools before it went up. The originals have the full detail.

A first-person survival horror game is not what the Game Boy Color was built for, which is part of the appeal of Save File 0. UK studio Ki10 Games, the two-person team of Mark and Scott, revealed it today for Halloween. Mark McManus told us about it through our tip form ahead of the reveal.

This is not a game made to look old. It is a native ROM written in C and assembly with GBDK, and the announcement devlog says it already runs on Mark's own original console from a flashcart. A dedicated prototype cartridge is still being made, and he plans to test its save memory when it arrives in November.

Two saves, one office

You are covering the night QA shift at Oriole Software, chasing a save bug nobody can reproduce. You make a save, open the index and find a second file you did not create. Load it and you are back in the same office, except that something else is now in the building.

Each save is its own copy of the building, and loading one puts you exactly where you are standing. Your own save is the quiet office. FILE 0 is the same place gone wrong, and it is where you get hunted. Puzzles come from swapping between them: a door opened in one stays open in the other, and racks that block a room in FILE 0 are absent from your save, so you walk round them and load on the far side.

The Occupant cannot be killed. A shot staggers it for a few seconds, then it is lockers, line of sight and running. Mark says more than nine years in games QA shaped the premise.

The hard part

The raycaster casts 40 rays across the screen, drawn as four-pixel wall columns, and aims for 30 frames per second using the console's double-speed mode. The devlog says getting the picture onto the screen is harder than drawing it, because video memory can only be touched in a gap about ten scanlines long. In an emulator set up to copy real hardware timing, Mark reports build 18 holding 30 frames per second in every room. He also says he uses AI tools to help with the programming.

What comes next

Ki10 is working towards a free playable demo. It wants a cartridge that keeps saves on the cart, a boxed edition with a printed manual and a digital ROM, but says there is no release date or crowdfunding announcement to share yet.

Sources

• Devlog #13: Save File 0 (Ki10 Games)
• Save File 0 project page (Ki10 Games)

Image: Ki10 Games