Being honest, I couldn't figure out the puzzles at first, it took me a while, but tbh I'm just really bad at puzzles. Something I think it's really unique about this game is the atmosphere and the visuals, like WOOOW I don't know if you guys used shaders or something like that, but the lightning in this game feels so polished, really well done! And the sound design also.
Also the part where you changes how the moon look just to open different doors, that's really creative ^^