Next Big Games has just dropped a free demo on Steam for Hold Your King, a physics-based co-op platformer that tasks 2 to 4 players with carrying a furious medieval King — and now his Queen — on a stretcher through a gauntlet of deadly obstacle courses. The full game is coming later, but you can wishlist it and jump into the demo right now. The Premise Is Unhinged and We Love It The entire game is built around one beautiful, chaotic idea: don’t drop the King. That’s it. Except nothing about it is simple, because the world runs on…