Played a bit. Some improvements to movement could be made. Not sure if you could, but make the player not stick to things when moving, but move to the side if something is just blocking the path a bit. For example, a protrusion on the wall prevents moving forward, the player should move to the side and still move forward. You can test for this by making a few collision tests in the direction the player is moving, and placing the player at an appropriate spot where it's not colliding. Some games do this for more fluid movement. Also, when running and going up stairs, the player will move deeper into the stairs and the movement will become jagged.