Welcome to The Design Conundrum. You can expect many entries regarding game play design, systems design, and alot of feature creep.
You start your project and say to yourself, "Self, im going to keep this small. I can add to it later, expansions, DLC, sequels, etc..." But it never stays that way. you inevitably dig deeper and deeper forking off of the feature/system that came before it. Its a hierarchy that can sometimes look like a family tree recorded back to Adam and Eve(If you believe that way) or Apes (if you believe that way!) or the mother ship (ok I'll stop).
At one point do you stop and say, "ok Self, enough is enough." Well I go about this in a way many of you probobly do. I never say that, and the project is never completed. Cool right? No. But hey, atleast your not alone. And misery loves company, so welcome scatterbrains, to The Design Conundrum!