GLitches
Great game! A few glitches though, making it easy to beat. Sometimes a material becomes 0 cost, making infinite money easy. Another time, on Hard, suddenly my debt went to -1.7 trillion (it had been +2 trillion at the time, as I never paid off the initial debt) and I was able to borrow 1.7 million from the moneylender and go to 0 debt. I was also then able to borrow off loads more; so much that I had 18 trillion and was in 17 trillion debt, not that it mattered because by then I already had the strongest fleet.
I believe you could have made the battle system more intricate and less repetitive, but that's just me.