I had a hard time playing the game because it wasn’t in full screen. Also, I couldn’t quite figure out what I was supposed to do.
If you haven't beaten the game, here's how. First, you need to search the entire house to find the safe. Then, find the key.
I found the safe, but I couldn’t see the key. Maybe I missed it because I couldn’t put the game in full screen.
Edit: The key was on the shelf. I must have missed it because the screen was too small. 😄