Alright... this is incredibly bare bones. No title screen, tutorial, or even any sort of controls outside of just movement so far. I do like the character sprite though sadly the enemy has no function yet. But it's a pretty strong start. As for the type of enemies to introduce in the next update, I would probably suggest you plan things out and connect the types of enemies with the sort of school environment that was once present. Whether it is, nurses, teachers, or perhaps a certain type of yokai or spirit. Yūrei come in quite a number of forms, but some pretty popular ones are like: Hanako of the Toilet, Hungry Ghost, Takkaona (Tall Woman) who I am guessing is what inspired the ghostly figure in the title of this game. There's a ton you could utilize and take inspiration from. But I think something that should be worked on is honestly the premise and story. Like, why are we investigating the school? What kinds of rumors, stories, and history does it have. What is it that makes those spirits linger, gather, and want to clap the protagonist's cheeks.
In regards to features, I just want to know what the gameplay's premise will be. How will we combat or avoid the encounters? I would recommend taking some notes not just from something like Fatal Frame but also FromSoftware's Kuon. How will you exactly explore and investigate? If you are taking the route of survival horror, do your best and try not to feel too hampered by expectations of what comes with the genre. My only advice with that is to properly test and find a balance in inventory management that doesn't feel too frustrating or extremely bottle necked. The last thing a player wants to do is run back and forth just to open up 1 slot or something. If there is something I would like to see in terms of weapons would probably have to be of course the camera, I think a simple white ray would work. A Fire Extinguisher would be neat to see, something to halt certain enemies. Salt would be a pretty handy one and something that could also be found in a place like this. But one kind of tool I hope to see would have to be any sort of charms or talismans that help escape any sort of grabs or reduce attacks from the enemies.
It has a pretty decent art presentation so far. Best of luck, I will keep an eye out for this one. Definitely will follow for further updates.