The Paradise Fortress of RePure Aria [English Version]

This is a 2D maze exploration pixel action game.
When a demon attacked the ordinary boy, he lost consciousness,
and awoke in a demon castle inhabiting the same body as that castle’s princess!
What’s more, because they now share a body they share all sensations and can change gender!
In order to get back to his body the boy needs to help the princess regain her memories.
Together they navigate a perilous castle full of alerted girl monsters.