In King Knight's stage, there is a room with a lava bucket that tries to prevent you from crossing a gap with moving platforms spanning the aforementioned pit. On the other side of this obstacle is, what appears to be, a Shovel Knight shaped hole and I don't know what to do with it.
I tried pressing Up,E,Space and every other key I could that that might interact with it but to no avail. Is it merely decorative? I mean the obstacle preventing you from getting to this hole isn't impossible, but it is a little unrewarding if this thing doesn't serve a purpose.
Best Answer
The hole is a secret passage. You don't press any keys to make it work, you just need to line yourself up with it fairly well and then wait a few seconds. Then you will be sent through the secret passage. I was too impatient to get it to work because I kept mashing keys and trying to re-align myself with it to let it actually trigger.