I know nothing about game development, but I can see that a useful analogy is with a big-budget TV series rather than a movie. Make a pilot episode first, full

I know nothing about game development, but I can see that a useful analogy is with a big-budget TV series rather than a movie. Make a pilot episode first, full production quality, and use that to greenlight (or not) the rest of the production. Even with one-off movies (or a hoped-to-be franchise) I'm aware that at least sometimes a test scene is shot and produced up to close-to-finished quality in order to win support for financing the full production. This could be a key point of dramatic inflection in a story/character led piece, or a demonstration of unique special effects ("bullet time" springs to mind here) if that is the USP of the proposed production. Like I said, I know nothing about game development, but if I was to get into that line for some reason I would want my business to be protected by taking a similar approach.