This engine and graphics set would also be a good basis for an ARPG.
You could visit tree houses, go to villages an enter the houses, talk to people and improve stats.
A whole quest could exist.
This should not be a quest game. Somehow I was in the mood for a classic platformer again :) RPG with quest order are not so easy. I'm still working on another project and it will take longer with the quests because I also want to tell a story.