Not a fan of the installer since it doesn't let you choose where to install and asks for administrative permissions for one install option.
The story just feels a bit convoluted. Where did the demon appear from? Passability issues, such as in the lab, hidden area... can't go further.
Game doesn't tell you where to find the horn you need and if you checked the ruined house before, you might not check it again.
Looks like the game ticks using a parallel event, which is fine except it doesn't tick in battle or menus, so you can end up with over an hour of playtime and still not trigger the end.
I managed to save mom, then next cutscene, I failed to save her?
You don't seem to be able to repick your class if you don't like it.
After battling in the ship, you have ships as party members in non-ship battles.
The changing of characters was honestly annoying. Just auto set our parties when we leave if you don't really have much of a choice. Or, since you have those pilot systems, make it so that you have a formation menu where you can set your ship vs land party members and have the game automatically set them for the appropriate areas.
The temple is almost completely messed up. A few seconds of playtesting that area could have found the issues.
You can't see how much gold you have, so you have to guess or remember how many mimics you killed (because the gold on the walls don't tell you that they are gold or how much, so you don't know which is gold, if any).
Looks like you used an event to represent the player and a light as the player in the mines. This looks odd because your light moves, then the event follows. You might want to change the movement appearance to be a bit longer so it feels less like the light is moving first and change the event to move a bit higher in frequency.
The guy just kind of takes your gold ore and then... ?
One of the islands can't be visited at all.
The moment of silence is like 15~20 seconds of silence?
Eventually I just kind of gave up on doing anything and waited for the time to run out because the game really doesn't tell you what you are supposed to be doing.