Very beautiful game! Loved all the references put in each of the world! There are so many really small details only fans would catch xD (god that snail and clover made me tear up). Music is also really nostalgic you gonna make real fans cry xD
A few things i might mention:
Mumeis question of what her fans THOUGHT the scary picture is based on might be a little misleading. I know it is based on suisei but if its about "fans thought" it might also mean what they see in that face (like it is really well spread as mumeis scary face rather than suisei).
I realized while replaying the game again, that the sprite layering may be faulty for the worlds?
Shioris sprite is always over guras sprite in guras world, shioris sprite is always behind mumeis sprite in mumeis world and with fauna its mixed/clipping through. as if gura is like layer 0, shiori and fauna layer 1 and mumei layer 3. might be worth checking. i would always put npcs behind the player character.
Other than that, the E for interact doesnt exactly work. likely cause thats a dev build as previously mentioned. (that also being the reason the dev console showed up for me at one point).
Anyways good work on that!