Quick answer
Mario 64-style platforming against an Elden Ring-style boss. Triple jump, long jump and ground pound around a soulslike fight with telegraphed attacks and a posture meter, then grab and throw the boss when it breaks. A clean-room tribute to ER Mario, with no game files.
The original game
Original game: Super Mario 64 × Elden Ring (clean-room tribute)
ER Mario by deltarooo put Super Mario 64's movement, health and combat into Elden Ring. It went viral as one of 2026's most surprising mash-ups. Hollow Warden turns the idea into a single boss fight that runs in the browser.
The browser version
You face a boss in the Ruined Arena with a full 3D platformer moveset: triple jump, long jump, backflip, side flip, wall kick, dive and ground pound. The boss telegraphs a sweep to jump over, a leap slam with a shockwave to hop, and a charge to sidestep, and it gets faster below half health.
Hits fill its posture meter. When it breaks, press E to grab, spin and throw it. Your health is an eight-wedge meter, and coins refill wedges. It is built in Rust and Bevy and compiled to WebAssembly, with original code and assets.
| Arena | The Ruined Arena, one boss fight |
|---|---|
| Moveset | Triple jump, long jump, backflip, side flip, wall kick, dive, ground pound |
| Boss | Telegraphed sweep, leap slam and charge; posture break into a grab and throw |
| Engine | Rust + Bevy compiled to WebAssembly |
| Browser | Desktop, WebGPU with WebGL2 fallback; ~60–120 MB first load |
| Game data | None: original code and CC0 or self-made assets |
How to play it
- Open the game in a desktop browser. The first load is about 60–120 MB.
- Space jumps (chain for double and triple), Ctrl crouches or ground pounds, and F dives.
- Break the boss's posture, then press E to grab and throw it.
Questions
Is this ER Mario?
No. It is an original tribute to the ER Mario mod and needs neither game.
Does it use Nintendo or FromSoftware assets?
No. Everything is original or CC0.
How do I beat the boss?
Read the telegraphs, fill its posture meter, then grab and throw it when it breaks.
Sources and coverage
- AI Game Mashups: Hollow Warden
- GitHub: andrewnakas/hollow-warden
- AI Game Mashups: tracker and tributes
- Awesome Game Mashups (GitHub list)
Fan projects change fast. Check the project's own page for the latest.