Yes, the king is in power but is really incompetent and he needs replacement. That's why a force from above (destiny ?) chose you to take his place with a remarkable entry (a mission that will make you hero through saving the world from collapse). The lava represents the previous failures of the king, hence their suspicious amounts. The cave under the bridge represents the inner quest needed to understand the world. Only those wise enough are able to skip it. That's just one interpretation lol :D
Majora's Mask was actually a big inspiration for me because it was a game I really loved back in the days. I think I might try recreating it in 2d godot (that is if I have enough time and skill lol)
Thank you for trying my game out ;)
P.S. Really liked your work, is there any chance you participate in other future jams ?