Achievements Question

[Epikas Jones]

So, a few of the achievements reference the word "stage" in order to unlock them. What exactly is considered a stage? one room or all rooms and the boss room that's with them?

[blankslatejoe]

A stage is an entire floor, from the "loading screen" to the exit elevator. Some stages, however, don't count toward progression, if I remember correctly (a few secret stages).

[Epikas Jones]

ah, ok thanks.