I agree on how the medium difficulty lack the chaos from the higher difficulties. Though I think it's still a needed difficulty.
My amazement on the achievement system may be because of my past experience with it. Previously I had a hard time implementing them, taking a couple of days to do it properly xD
That's good to hear that this game didn't suffer from overscoping. I also tried to not do too much with my game, but I still almost didn't finish the game lol.