I'd still try to focus on making a playable, dumbed down version of your idea in like a month or two. Get something done you can have a friend play, it can make all the difference.
seconding. I've made the mistake of making games without feedback at an appropriate time... had to re do a lot of combat and animations. (my animations and times made the game too unresponsive for its genre/ other mechanics)
speaking of which, i should take that advice and have my friends/ family check out my current game's gameplay before i get too far XD so thanks for the reminder!
also, as fire7side says, it would be a decent idea to start with a simpler game. I started WAY too ambitious for my first project, back when I did unity... even if you have perfect ideas and implementation, i've gotten way further in my current game in godot, which is much simpler, and makes me feel more accomplished knowing I'm so much closer to done than I would have been earlier. I think being able to release one game that's simpler would be good, then you'll know what to do and not to do for at least some bits.
sorry if that didn't make sense :X it still early here, but i hope you get what i mean about the simpler games.