A couple of questions in case anyone knows [spoilers]

[XENOpz]

How do you get the "Uncovering Secrets" achievement?
How do you get the "I could use a vacation" achievement?
How do you get the real ending other than through "Chapter Select"? I assume it's to do with the mirror but nothing I type in does anything (and I've tried all the names in the game). The one thing that does something is luzia but that just seems like an easter egg. It's just a couple of voice lines that do nothing.

Thank you!

[MegaMix_Craft]

I'm not giving you exact solutions, but here are few hints:

How do you get the "I could use a vacation" achievement?

booklet

How do you get the real ending other than through "Chapter Select"?

Listen to what red text tells you before Break or Strengthen chapter

For the last one, just uncover the secret

[XENOpz]

Thank you, got the first two. Still haven't uncovered the secret. Best I could do is reenter the secret cart and soft-lock myself out because there's no way to exit if you enter a second time. :P

[Stranga]

The uncovering secrets is within the first chapter not the prologue. ;)

[XENOpz]

Thank you! That helped!