I'm trying to knock over the shelf to be able to crawl through the tunnel, but I can't knock it over. Can you help?
Are you talking about the first self in the game,
I believe so. It's in the same room where you picked up the hammer. Then I took the hammer and smashed the boards to a tunnel. I just can't push the metal shelf over to get to the tunnel.
Apparently Philip is not strong enough to knock the shelf over with his hands alone. Instead, grab the shelf and try moving around with arrow keys.