Sonic Adventure Cdi 〈2026 Edition〉

Play it if you dare. But keep a save state handy. And maybe a bucket. You’ll need both.

To save costs, Phantasm outsourced character animation to a small studio in Bratislava that had previously only made a stop-motion toothpaste commercial. The animators were given a single reference sheet: the Adventures of Sonic the Hedgehog cartoon, paused on a frame where Sonic is screaming.

Its emergence has sparked a new wave of digital archaeology. Was it a hoax? The emulator code suggests not. The unique CD-i subroutines, the specific hardware bugs it triggers, the proprietary video codec—it’s real. It is a genuine artifact from an alternate timeline where platformers were built by the clinically depressed and voiced by the terminally confused. Sonic Adventure Cdi

In a baffling decision, the composer—a friend of Van Der Berg’s who owned a Korg M1—was told to make “jungle music, but sad.” The soundtrack of Sonic Adventure Cdi is a 32-minute loop of detuned breakbeats, a crying saxophone sample, and what sounds like someone dropping a toolbox in a swimming pool. The main theme, “Blue Is the Color of My Trauma,” has no lyrics—just a vocalist whispering “go fast… go fast… stop being slow…” over a diminishing 303 bassline. After months of restoration and error-correction by a collective of masochistic data hoarders, a playable build of Sonic Adventure Cdi was finally emulated in December 2024. It is, without hyperbole, the worst thing ever coded.

The result is… something else. Sonic’s model is a 3D-rendered abomination—eyes too wide, quills that clip through his own torso, a mouth that animates independently of his face. When he spins, he doesn’t curl into a ball. Instead, his limbs snap to his sides like a man falling down an elevator shaft, and he rotates around his own spine. The spin-dash takes 4.7 seconds to charge. Testers reported nausea. Play it if you dare

This is the story of the game that wasn't. The game that shouldn't be. The game that redefines the word "unplayable." To understand Sonic Adventure Cdi , you must first understand the Phillips CD-i. Launched in 1991, it was a multimedia “player” that also played games, boasting a staggering 1MB of RAM and a green-book CD format that could store full-motion video. In practice, it was a catastrophe. Its processor was sluggish. Its controller was an ergonomic war crime (a plastic slab with a click-wheel and a number pad). And its development tools were, by all accounts, a form of psychological torture.

Early footage—recovered from a corrupted DVCAM tape—shows Sonic rotating on the spot while a blurry checkerboard pattern scrolls behind him. A debug counter reads “SPEED: 0.0.” A post-it note visible on a monitor reads: “Velocity not possible. Increase friction?” You’ll need both

And then, lurking in the shadowy back alleys of ROM forums and lost Geocities archives, there is the ultimate white whale: .

Sonic was going to the devil. The developer assigned to the project was a small Dutch studio named Phantasm Software , known only for a forgotten golf game and an interactive encyclopedia of mollusks. Led by a manic, chain-smoking programmer named Henrik Van Der Berg, the team was given eight months, a budget of $150,000, and a single design document: “Make it like Mario 64, but on CD-i.”

It is terrible. It is broken. It is, without question, the greatest Sonic game never made.

The first problem was 3D. The CD-i had no native 3D acceleration. Its CPU could barely handle sprite scaling. Van Der Berg’s solution was both brilliant and insane: a software renderer that drew the world as a series of flat, parallax-scrolling “corridors.” Sonic wouldn’t run in a 3D space. He would run on a treadmill while the background slid past him. The team called it the “Hamster-Wheel Engine.”