You see the image below you?

You get the first star by beating the main game. But the second star is a bit more complicating. Let me explain.

This is the Crane Machine.

This is the machine where you get the Key to the final door.

But it can also be used for this:

There are two plush toys in the Crane Machine.

(I got one from this save file).

If you check one of the dolls it will give you a prompt to stare in the doll's eyes.

Select "Stare back".

Once you do that you'll see [SPOILER]

After that go to an arcade mini-game that is available (Use save files for a better experience).

Like this one:

Play the game. Then do the order like the doll said. When you complete the order you'll get a [SPOILER]

After that you completed one out of three mini-games. Gotta let you know that the two dolls contain the clues you need. The last one... I'll just say that the last Arcade mini-game is still on after you beat the brown rabbit.

And that's how you get the second star and the extras menu in Hind Sight 2.

Hopefully this information was helpfully. Let me know if you want more secrets and tell me if you know anything that I don't know about.