How do I open the door?

Hint 1 of 5:

You never know what might be behind door #1.

Hint 2 of 5:

Saving your game is a good idea right now.

Hint 3 of 5:

Remember the locked door in the castle that wouldn't open?

Hint 4 of 5:

Remember the crown symbol impression on that door?

Hint 5 of 5:

See the little button on the wall? Push it!