I’ve built three separate things. A game server, a game engine and the game itself.
The game server allows multiple people to play together in multiplayer mode. The game engine is the technology powering everything, including the real-world maps, roads, environments and how the game functions.
The game itself is what people actually play, and it’s already playable.
These are 3 different components that work together. The engine is not the game, the game is not the server and the server is not the engine. The engine can run without the game