Steins;Gate: Hen'i Kuukan no Octet (Variant Space Octet) is a non-canonical sequel to the original visual novel, designed as a retro "8-bit" text adventure game. Key Features

However, something is wrong. Reality begins to glitch. You control Kaito, an amnesiac who realizes he can manipulate the "Octet"—eight possible choices (actions/thoughts) at any given moment. As you progress, you discover that a "Variant" is trying to collapse the attractor field.

Okabe froze. That wasn't just a game. The pixelated art showed a blocky, 8-bit version of the lab, but the text scrolling at the bottom was a direct transcript of a conversation he’d had with Kurisu only ten minutes prior—a conversation no game developer could have known.

The Short Answer (No Spoilers)

There is no official standalone game called Steins;Gate: Variant Space Octet currently available for sale on Steam, Nintendo Switch, or PlayStation.

Style: 8-bit visual novel with text-command input (e.g., "look," "move," "open").