Orcs Must Die! 3

Gear Slots are Unlocked as you complete levels and progress through the first campaign. I unlocked the final gear slots and the achievement after completing the Third War Scenario which is Level 11? I think. I was on Rift Lord Difficulty but I don't think that matters and you aren't required to get a minimum score, just successfully finish the level which means completing all waves and having at least 1 Rift Point left at the end.