Sonic.EXE – The Original Game

Sonic.EXE is a horror-themed Sonic fan game that mixes familiar platforming with disturbing imagery and tense chase scenes. Developed by Adam Gavigan (MY5TCrimson) and first released in August 2012. Players move through corrupted versions of classic Sonic zones, where the environments feel empty at first but slowly shift into something darker. You can play it fast and easy on kbhgames.com for free with no installation, directly in your browser.

The game follows three characters — Tails, Knuckles, and Eggman — each getting their own level. Tails starts in a stripped‑down version of Green Hill Zone, where dead animals and brief glimpses of Sonic.EXE make the area feel unstable. Eventually, Tails is forced into a burning version of Angel Island Zone, where Sonic.EXE hunts him down.

Knuckles’ stage takes place in a red‑sky version of Scrap Brain Zone. The level becomes more hostile the farther he walks, ending in a brief, one‑sided encounter where Sonic.EXE teleports around him until Knuckles collapses. Eggman’s level is slower, built around long staircases and repeating backgrounds that feel like a loop. It ends with Sonic.EXE confronting him and the message “I AM GOD.”

After these events, the game shows a burning “GAME OVER” screen and a poem in Japanese that doesn’t progress unless certain secret steps were taken.

Players can find hidden areas by running left in specific levels. These secret paths lead to short, unsettling stages that include glitch effects, distorted music, and messages from Sonic.EXE. Each hidden area contains a black Ring, and collecting all three unlocks a translated version of the poem at the end. If all Rings are collected, an additional hidden sequence appears where players control Sonic in a static‑filled void, surrounded by flashing faces and more messages, before the game eventually locks up.

Overall, Sonic.EXE uses familiar Sonic settings to build tension and show a corrupted world, and the secret paths add extra lore for players who want to explore deeper. You can try the full experience on kbhgames.com at any time, right in your browser.