Please note: all credit goes to mooware!
Where to find the Stork and the Anvil Mode after beating the game.
Stork and Anvil Mode
After beating the game, a popup will tell you that you can now visit the stork for a level select, and try anvil mode. But it is not obvious how to find either of these.
I couldn’t find it myself either, but luckily a youtube video explained where to find them. I’m putting it in this guide to make it easier to find.
To get to these unlocked features, start a new game, then in the house go up to the second floor, and walk through the right wall.
There you will find the stork. Talk to it to either select a stage, or to select Anvil Mode. In this mode, you will wear an anvil instead of a hat, which has much less reach when thrown. You will also die from a single hit when not wearing any hat.