Demon Flex
A free 3D third-person shooter prototype in the browser: a steampunk demon hunter trapped in Hell saves souls, finds keys and lands headshots for points. The developer says the whole game was vibe-coded in JavaScript with Grok and Claude.
Official site getalife-games.itch.io, verified Nov 3, 2026. The developer's own itch.io page (getalife_games).
Where to play
Every platform this game is on. Links are checked against official sources; we never host or mirror games.
- Play free — itch.ioitch.ioEarly access · Prototype (per the itch.io page)Free
Plays in the browser on itch.io. No download.
Browser (no download) · Official link verified Nov 3, 2026.
About Demon Flex
Demon Flex is a free 3D third-person shooter that plays in the browser, listed on itch.io as a prototype. You are a steampunk-looking demon hunter trapped in Hell, and the only way to salvation is to save as many souls as possible and slay demons with a range of weapons. Points come from demons killed, souls saved and the time taken for each level; headshots kill two-legged enemies instantly, give bonus points and restore health. Some rooms are behind locked doors, and killing certain demons reveals keys and power-ups. Ammo is limited: three dagger slashes on an enemy spawn more ammo somewhere on the map. The score carries over from level to level, but dying loses all your points. It works best with a gamepad, with keyboard and mouse also supported and a lock-on aim; touch controls are listed as coming soon. The page's short description calls it a homage to old-school 3D third-person-shooter games like Doom. The developer, getalife_games, a one-person studio, says the entire game was vibe-coded in JavaScript using Grok and Claude, with MidJourney for the graphics and Suno for the music, and that the sound effects are the only part made without AI. The developer entered it in the 2025 Vibe Coding Game Jam. Free on itch.io, with optional donations.
How it was built
Partially verifiedThe itch.io page says the developer vibe coded the entire game in JavaScript using Grok AI and Claude, with MidJourney for the graphics and Suno for the music, and that the sound effects, made by the developer, are the only thing created without AI. Grok (xAI), MidJourney and Suno are tools we do not track. The page also says the game took months, despite AI doing much of the heavy lifting. It does not say which parts of the code Grok or Claude wrote, or which Claude product or model was used. The itch.io AI disclosure ticks AI Assisted, Code, Graphics and Sounds.
Vibe-coded in JavaScript with Grok and Claude over several months, per the developer, with AI-generated graphics (MidJourney) and music (Suno) and hand-made sound effects. The developer plans more enemies and weapons (grenades, flame throwers, a shotgun and a sniper rifle) and online multiplayer if players like it.
- Engine / framework
- Not disclosed (JavaScript browser game)
- Languages
- JavaScript
- Team size
- 1 (solo)Developer Reporteditch.io
- Initial build time
- Not disclosed
- Development time
- Not disclosed
- Development cost
- Not disclosed
- AI-written code
- Not disclosed
“Vibe coded the entire thing in JS using Grok AI, Claude, MidJourney for graphics and Suno for music.”Verification notes: AI use, gameplay and controls from the developer's itch.io page (read on 4 Nov 2026), which lists the game as a prototype and ticks AI Assisted, Code, Graphics and Sounds. itch.io shows no publication date; the developer's post on the game's community board (23 Mar 2025, 19:45 UTC) says it had been entered in the 2025 Vibe Coding Game Jam organised by levelsio, so it was public by then. The entry was not checked against official jam results. Team size 1 from the page's “My One man Indie Game studio”. The page's short description calls the game a homage to old-school 3D third-person-shooter games like Doom, and the page tags it Doom; no source mentions Doom names or assets in the game, so no IP notice is attached. Grok is recorded only in the usage text because we do not track it as a tool. The game contains violent combat against demons; no age rating or content warning is given. The game was not played; nothing on the page describes AI used during play.
Development history
The developer posts on the game's itch.io community board that Demon Flex has been entered in the 2025 Vibe Coding Game Jam (#vibejam) organised by levelsio, with online multiplayer and more weapons in the works.
Game performance
Each figure measures something different — concurrent players, owners, downloads and sales are never interchangeable and are never added together. Labels show where each number comes from.
itch.io
Free in the browser (HTML5); itch.io suggests an optional US$2.00 donation.
No public metrics recorded for this listing.
Not publicly available: itch.io rating, Gross revenue.
Sales & revenue (all platforms)
Browser game — there are no downloads to count.
Reviews & rankings
Not yet reviewed by our editors.
Not currently ranked.
Sources
| Source | Type | Published | Accessed |
|---|---|---|---|
| Demon Flex by getalife_games itch.io | Store page | Not confirmed | Nov 3, 2026 |
| We’ve entered Demon Flex into the Vibe Jam game contest itch.io (Demon Flex community, getalife_games) | Social post | Mar 23, 2025 | Nov 3, 2026 |
| Official game page (language check) getalife_games | Official site | Not confirmed | Nov 3, 2026 |
