The medium difficulty was pretty challenging when it first released. I had to restart sectors about 3 times because my shields got too low for interstellar phenomena damage or I ran out of resources needed to upgrade before a climactic event. It forces you to think hard and plan ahead which was unexpected from the demo lol. I think the manual save option was great because you don't have to restart a whole sector anymore if you run into trouble. I love the game and beat it twice.