Building with Stage Engine needs a connection. Playing what you built does not.

There is no offline mode. Building needs an internet connection, because Director 1, asset generation and world data all come over the network, and the game you built runs locally on your own machine and needs nothing at all.

Both halves of the answer

Building a game with Stage Engine needs an internet connection. Playing the game you built does not. Those two sentences are the entire answer, and this page exists because people get it wrong in both directions.

One wrong picture has the whole thing running somewhere else: a server rendering your game and sending you the pixels, the way a cloud gaming service does. That is not what happens. Stage Engine is a desktop app for Mac and Windows with a copy of Godot inside it, and when you press play the game runs on your own processor and your own graphics card.

The other wrong picture has it working on a plane, on the grounds that it is a download rather than a website. It will not. Without a connection you cannot build, and no amount of having already installed it changes that.

What actually goes over the network

Three things. Director 1, who writes the GDScript for your game and runs on hardware we pay for. Asset generation, when you ask for something that does not exist yet. And world data, which is what the builder pulls in when your terrain is based on somewhere real.

Your project is not one of those things. It lives in a folder on your own disk as an ordinary Godot project. It is not uploaded for the game to run and it is not being held on our side. The connection is carrying requests and results, not your game.

What runs on your machine

The app and the engine. Godot ships inside Stage Engine, so pressing play starts a real game process on your computer at whatever framerate your computer manages. No render queue, no streaming, no browser tab in the middle of it.

That is why a large world is a reasonable thing to attempt here. Terrain, weather and a few hundred characters moving about are not things a browser tool runs smoothly, which is why browser tools quietly steer you towards small flat scenes and rarely say why.

It is also why the game you finish is a normal program. Somebody you give it to installs it and plays it, with no account, no connection and no copy of Stage Engine anywhere on their machine.

Why there is no offline mode

The models that write your code and generate your assets run on hardware that cannot be shipped inside a desktop app. An offline mode would have to be something much smaller wearing the same name, or a promise that fails quietly at the exact moment you were relying on it.

So there is not one, and there is not going to be one. If a dependable connection is not something you have while you work, this is the wrong tool, and it costs you nothing to find that out before you install it rather than after.

There is no degraded mode either, and that is a decision rather than an omission. A tool that half works when the network is bad is a tool that leaves you wondering whether the problem was your idea.

When the connection drops

You stop being able to build. Asking Director 1 for a change needs the network, and so does generating an asset. That is the practical shape of it, and it is worth planning around if your connection is unreliable rather than absent.

What does not stop is everything already on your disk. Your project is a folder of files, Godot is free and open source, and a build you already made is a program that runs without checking in with anything. A dropped connection does not put your work out of reach or hold it hostage.

The two questions worth keeping separate are whether the tool needs the internet and whether the game does. The tool does. The game does not, unless you deliberately build a game that does.

Questions

Can I build a game on a plane?
No. Director 1, asset generation and world data all come over the network, so building needs a connection.
Does the game I built need the internet to run?
No. It runs locally on the copy of Godot that ships with the app, and the build you hand to a player runs on their machine with no connection.
Is there an offline mode?
No, and there is not going to be one. The models that write your code and generate assets do not run on a laptop.
Is my game streamed from a server?
No. Nothing is streamed or rendered remotely. Press play and the game runs on your own hardware at your own framerate.
Are my projects stored in the cloud?
No. They are ordinary Godot projects in folders on your own disk.
What exactly needs the connection?
Director 1 writing your code, asset generation, and world data for terrain based on real places. Everything else is local.