I liked that this included the question "What is the minimum viable product?". It reminds me of a game design article I read a long time ago, which mentioned that the best way to figure out if you have a game that will be fun when it's finished is to "start with the stupidest thing that could possibly work." In other words, starting small and focusing on the core mechanic, and building on that only once you've "found the fun," is a reliable way to produce fun games. This is in stark contrast to the way many projects are run (game or otherwise), in which thousands of features are planned out right from the start and presumably developed in parallel, like a hundred people simultaneously trying to stuff themselves through a single doorway.