Planetary Egg City
I don’t know this is intended or not but I think it is going to lower the difficulty a lot you meet the Planetary Egg City. When the boss deploys chicks, I find it really easy to find firepower that dropped from them (the chicks). In difficulty 90% - 100%, I can just shoot them and farm for fire powers and make the rest of the mission really easy. With The Egg Cannon boss, it’s the same, chickens deployed from it have a high firepower drop rate too, but it’s harder to farm than Planetary Egg City.
The same with the Apple core boss, the barriers drop a lot of fire powers but the difference is you can’t stay there and farm because they aren’t infinite like the chicks.
I find that when the parts of Alien Mothership fell down they usually fall with a firepower or a random weapon. I find it really annoying that parts and the firepower (weapon gift) fell in same place with the same speed, sometimes it’s impossible to pick them up when they in the middle of the part.