There are some interesting ideas here! I like the idea of a first-person examination mechanic in a 2D side-scrolling world. Unfortunately it is pretty unclear what to do/where to go in the game. I eventually found the key and went down the stairs after reading your note, but I never would have noticed that on my own. I'd recommend changing the key's color to make it a little easier to see. But after I found the other hallways, I couldn't figure out what to do next. I'd recommend adding some more player feedback and signposting to communicate what might be an important thing to look at. Overall, this is a nice start, keep working on it!