I like that you made an adventure/exploration game.
I also like that your levels have multiple paths to explore. I would like to see you expand on that, making the different paths interesting in distinct ways. Currently some of your paths don't feel very rewarding or exciting.
Your use of shadows to make switches harder to spot was cool. I'd like to see you have at lot more switches or things to find in the shadows.
For a game titled "Abandoned Mansion," it doesn't have the mood of one. I think changing your colors could help. How about black walls instead of white? Also maybe you can create more a sense of being in an abandoned mansion with the shape of your rooms. Currently, the rooms feel like random shapes.