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Flatline: The Shiba Circuit

Year	2026
Publisher	a2cogs
Developers	Rob Perissi
RAM Requirement	2 meg RAM (4 meg recommended)
Control	Keyboard, Joystick
Other Requirements	ROM 01 or ROM 3. On 2 MB a match load can come back NO MEMORY at the VS screen; Esc and pick it again. Runs on a stock IIgs; smoother with an AppleSqueezer, TransWarp GS or Zip. Network play needs a CoGS card on Wi-Fi or Ethernet in each machine.
System 6 Compatible	Yes (boots its own GS/OS 6.0.2)
Hard Drive Installable	No (a 32 MB boot volume; write it to a CF or SD card, or mount it in an emulator)
Release Status	Free download. Flatline: The Shiba Circuit is copyright 2026 Rob Perissi.

About

Flatline is a one-on-one fighting game for the Apple IIgs, written in 2026. Eight fighters, each with a home stage, a fighting style and one special move, and the Grid for mirror matches. The Marais-Rand house runs a fight every winter on the dime of Shiba's black market bio clinics; the prize is a clean identity, a new liver and a way off the circuit. Wade boxes like a dockhand and throws the Ice Break. Sable is freelance bladework with the Razor Cyclone. Rook keeps the Kobo and swings a surplus arm. Kessel hears a fight a beat early and sends the Dub Drop along the floor. Kuro is one of many guards with the same face. Vane is what the war left of a colonel. Rodrigo dances capoeira in the Souk. Lady Marais, who runs the circuit, fences.

Three ways to play. One player climbs the ladder: six fighters in a shuffled order on their home grounds, then yourself in the Grid, then Lady Marais at The Core, with Easy, Normal and Hard and a ten-second continue. Two players share the keyboard (P1 on the arrows with Z and X, P2 on W A S D with G and H; keys come straight off the ADB keyboard so both can hold keys at once) or one takes an Apple II analog joystick, read as an eight-way stick with button 0 punch, button 1 kick. Block by holding away. The special is down, forward, punch for everyone. Esc pauses; Esc again leaves the match. Two rounds of three win a match.

With a CoGS card in the machine the title gains N, a network game through the Game Room lobby at a2cogs.com. Type a name and a room code (or leave the code blank to take the next player in) on two Apple IIgs machines anywhere on the internet, pick your fighters on your own screens, and the match runs in lockstep with three ticks of input delay, the same frame on both machines; the card carries the inputs. Pause shows on the other machine as THE OTHER GS PAUSED. Without a card the line reads G, a page about what the network game is.

The screen is Super Hi-Res 320 by 200 with a palette per scanline band, so the stage, the two fighters and the blood share sixteen colours a line. The simulation runs 30 ticks a second whatever the frame rate does, and draws 14 to 18 frames a second; hit, hurt and block boxes per frame. The fighters were rendered from motion capture in Blender, toned to the GS palette, and are compiled to code on the GS while the VS screen covers the match load. Sound is the Ensoniq: eleven songs (a title theme, one per stage, the Grid and the ending), an announcer, and the fighters' grunts, all on the chip's oscillators at once.

The download is one 32 MB ProDOS volume, GS/OS 6.0.2 with the game as System/Start, so it boots straight into the title. Write it to a CF or SD card for a CFFA or similar, or mount it in an emulator. CoGS owners boot it from the card's disk catalog (Browse, Featured, Flatline) with nothing else in the machine; streamed from the card each match load is a few seconds, and card firmware 1.41 keeps the music playing through them. The .2mg is the same image with a 2IMG header for emulators that want one. Overview, manual and move lists at a2cogs.com/flatline.

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