So I lit my simple level 1:
Initially I just lowered the direct lighting and put point lights over the platforms and a spotlight on the character, but I think it really came together when I moved the direct lighting around to be back-lighting the scene. I’m not sure why back-lighting reads more as moonlight but it seems to. Also the main light coming from the top right where the exit platform is means that the mouse is moving towards it on his journey to the moon, which seems thematically appropriate to me.