© 2026

Free build

Skip the missions. Empty canvas, node-based editor, live graphs. Drop in components, wire them up, hit run, see what happens. Good for "what if I just…" experiments.

Recreate real engines

Same components, same physics. Build a Merlin 1D from scratch. Or an F-1. Or something that's never existed and probably shouldn't. Push materials, propellants, and geometry until something gives.

Key features

• Mission Mode with real engineering challenges. Guided builds with senior engineer Miku Aoyama, from your first model to a complete gas-generator turbopump cycle.
• Live performance graphs and samplers. Chamber pressure, thrust, Isp, and thermal margins update in real time, with pump and turbine performance curves you can sample as you tune.
• 2D node-graph assembly. Drop in components, wire them together, and fire the engine on an open canvas.
• Real physics, no shortcuts. Combustion, fluid dynamics, and heat transfer through regenerative cooling channels, all solved in real time.
• Recreate real engines. Build a Merlin 1D, an F-1, or a Vulcain 1 from the same components and physics.
• Display Units. Read every output in the units you actually think in, from kN to bar, across charts, samplers, and mission text.

Pro Content (optional add-on)

Soundtrack, technical reference PDFs, 3D-printable component models (STL/3MF), and high-resolution wallpapers. For the people who want the lore in their toolbox.

What's new

• 0.5.0: Mission 0, your accidental first day on Miku's workstation. Three new gas-generator cycle missions (Turbopump Integration, Gas Generator Genesis, Injector Insights). Display Units, so you can finally read pressure in bar instead of pascals.
• 0.4.0: Real-time pump and turbine samplers with live performance curves. Auto-run on every edit. Pinned component editor with nudge buttons and mouse-wheel tweaking. Colorblind-safe chart colors (Okabe-Ito).
• 0.3.0: Multi-select and copy-paste in the schematic editor. Plus a pile of stability fixes for selection and menus.

Early Access roadmap

Meco is in Early Access and playable today. The full core loop is here: design an engine, fire it, read the graphs, and iterate. I ship updates regularly. Here's what's already in, and what I'm building next.

Playable now:

• Missions Chapters I to IV: Mission 0 through Mission 12, from "what's a model?" to complete gas-generator turbopump cycles
• Thrust and Isp measurement

Building next:

• 3D nozzle design and flow separation (in progress)
• Missions Chapter V, "Building On The Past": recreating historic engines
• 3D pump impeller, turbine rotor, and stator design
• Component mass, for thrust-to-weight numbers
• Thermal and load stress limits
• Historical campaigns

This roadmap can take a few years to finish. I build Meco solo, so every purchase directly funds the work, and if enough people who think like you buy it, I can do this full time. Your support genuinely makes the difference.

Dannie Sim

Solo Indie Dev, Meco Rocket Simulator (formerly at Activision/Blizzard on Candy Crush and Sony PlayStation on Spider-Man 2)

Heads up

This isn't a casual arcade game. It's a serious engineering sim with a real learning curve, and honestly, your first designs probably won't hit their targets. That's the point. When a build misses, the sim tells you exactly what is wrong and walks you to the fix one item at a time: run