Oh, whoops, almost missed this comment! The hardest part was the moment I realized I had to program triple seed fusions and my initial formulas were VERY broken. In the end I coded an entirely different system for how it functions, but I think it turned out pretty well in the end! :) That was probably the biggest thing in terms of difficulty, in terms of time that would definitely be the UI, I think a solid half of the time was working that out lol