Achievements bugged?

[skatche]

I just reached Room 46 for the first time. (I'll give more details below in case there's something missing, just want to give a buffer for spoilers.) However, I don't have the achievement. Is this a bug?

There are a lot of puzzles that I haven't solved yet. However, this is how I won: I made myself a power sledgehammer, which I used to get into the basement from the grounds. I had already solved the puzzle in the tomb, and moved the minecart, so from the far side of the reservoir I was able to reach the lever that opens the north exit of the antechamber. Did this at the start of a run, managed to find the lever in the great hall that opens the east exit of the antechamber, got to the antechamber and exited into room 46. Got treated to The Red Prince with its original ending, and credits rolled. But no achievement. I've never actually used the Basement Key, if that makes a difference -- didn't need to given this method.

[Raptor]

Congrats on making it to room 46!

You'll be able to pick up an in-game Trophy in the very near future.
Doing this will grant you the achievement you're looking for.