Did you speak to the succubus in the casino? You get disguises for the trip.
I'm trying to remember which quest Royal Trouble is. Given your response, I'm thinking about the part where you already saved the princess.
If this is where you're at, let me tell ya what I know works.
1) Inflate the princess via seeds in her chambers (bottom left of the third floor with the King and Queen)
2) Go belly goblin mode by getting 50 seeds for the underground peeps. If you need the code, talk to the clown for a bit or buy your way to it.
3) Talk to the queen after the fact. That should allow you to deal with "Like Daughter Like Mother" quest. I am calling it this 'cause names are hard.
4) Get the goddess to help out.
5) Expand the Queen by giving her what she wants.
This should complete all of the Royal Troubles. I hope this helps a bit.
Purple Fier? Pink Place? Oh you're talking about the Stewart and the demon dungeon that closes off after you're done with the quest.
Given that you also got the Valkyrie wings for Leia, I'm guessing you need to do the following:
- Go north from the desert until you see a Snowy Island.
- Finish the quest within the city of steam. (Brasswell if I'm correct)
- Go to the Igloo back on the snowy island when you can leave the city.
That should allow you to finish off what is currently available in the game. Other than that, you just have "side quests" to deal with. Most of them are unmarked in the Quest Book, so keep an eye out for them and keep an eye on the dialogue.