Yeah scope is kind of a hard thing to figure out. I've started making a ton of games that I had an entire semester to finish and even then I didn't get anywhere near finishing a lot of them. I think for stuff like this, it's best to focus on your main mechanic first and flesh that out as much as possible, then work out from there. Story, art (especially music), extra mechanics or difficulty, those are all things that aren't totally necessary to a game, but rather enhance the experience. I think this is the first time I've gotten that process correct tbh