That was an amazing proof of concept for a metroidvania!!! It was even really polished with this minimalistic look. The dialog box and the concise dialogs were great, most people write texts and texts and it makes dialogs so boring, but yours made the game flow naturally.
The controls are perfect, the wall jump was very natural and well implemented (hardly seen so well implemented in game jams, most people mess up the velocity).
The only problem is the confusing returns. One of the key features of metroidvanias is exploration. Sometimes I went through a door and I came back to a different place from where I left and it was confusing. Doors need to me interconected, you need to always return to the same door or the player will get lost. Also you need to save states between rooms, like the guys guarding the doors, if I lost I had to ask them again to let me through.
Still, those things are easy to fix. Again, amazing proof of concept for a metroidvania. Good job!!