Mostly Modular — Game Engine for Builders

Game development energy — colorful game worlds floating in purple space

Your Game. Your Rules. Ship It.

Don’t Panic: Mostly Modular works with the language you already know, fills the gaps with AI, and gets out of your way.

What You Get

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Build Games Your Way

This isn’t a switch with two positions. It’s a slider. Bring as much or as little as you want. Your skills, your workflow, your call. The engine adapts. You don’t.

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Ship in Days, Not Months

Prototypes should be fast. Ideas should be testable. With MM, you go from concept to playable in days. Spend your time making it good, not just making it work.

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Write It in Whatever Language You Want

Rust, C#, Go, Python, JavaScript. Pick the one you actually know. No learning a proprietary scripting language just to make a rectangle move. Just write code.

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AI That Knows the Engine

mm-assist is baked in. Not bolted on. It knows the codebase, the APIs, the patterns. When you’re stuck at midnight wondering why your collision is backwards, it’s there.

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See It Change Instantly

Hot reload means you edit, save, and watch it update in real time. No restart. No waiting. No breaking your flow to see if a number changed. Just build.

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Build Once, Use Everywhere

The plugin system is how you stop solving the same problems twice. Build a camera controller, a save system, a HUD. Plug it into the next game. Done.

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Free. Open Source. For Real.

No subscription. No per-seat pricing. No “basic plan” that hides all the useful stuff. MM is free now and free forever. Fork it, ship it, do whatever you want.


Games Built With MM

These are what we’re building toward. Real games. Real code. MM doing the heavy lifting.

Orbit Ball — Spin. Dodge. Don’t Die.

You’re a ball with one job: orbit the planet without hitting anything trying to kill you. The physics feel tight and satisfying, and building that in MM took about a weekend.

Orbit Ball gameplay showing glowing ball orbiting a planet in space
Orbit Ball showing combo multiplier explosion

Prism Break — Light Bends. So Does Your Brain.

Redirect light beams through crystals to hit the targets. Sounds simple. Gets weird fast. The whole puzzle system was built with MM’s plugin architecture, start to finish.

Prism Break puzzle gameplay with colored light beams and crystal grid
Prism Break level complete screen with three stars

Starfield Run — Speed Doesn’t Wait for You.

It keeps getting faster. You keep weaving. Eventually something wins. The endless runner loop was up and running in MM in under two days, hot reload the whole way.

Starfield Run with spaceship dodging obstacles at high speed
Starfield Run showing narrow danger zone corridor

Fleet Command — Territory Is Won One Move at a Time.

Manage your fleet, pick your battles, expand across the star map. The strategy layer that took weeks in other engines came together in MM because the state management just works.

Fleet Command top-down tactical space battle view
Fleet Command fleet management UI panel

Deep Space — Something Out There. Find It.

An alien station, a missing beacon, and a lot of dark hallways between you and it. The world-building tools in MM let us build the whole environment modularly, piece by piece.

Deep Space atmospheric alien station interior
Deep Space bioluminescent alien creature encounter

Ready to Build?

Download is free. Always will be. Docs are there when you need them. The only thing left is your idea.