The endings, along with the binary paths to obtain them (1 for following directions, 0 for not) are:
Ending 1 (11111-):
The more Steve searched, the more certain he was of his fear: the story of life on Earth would end with him.
Ending 2 (111101):
Steve was somehow so supremely satisfied with the soft click of the smooth button that he decided to click it again. And again. And again...
Ending 3 (111100):
And ever since he entered that door, Steve was not found.
Ending 4 (1110--):
Well, Steve, I think you broke it. Good job.
Ending 5 (1101--):
But Steve miraculously cleared the dungeon, and stumbled upon a prize beyond measure.
Ending 6 (1100--):
But the monsters quickly dispatched Steve, and returned to wait for more unsuspecting adventurers.
Ending 7 (101---):
I didn't expect that, Steve. I'm sorry for leading you astray like that.
Ending 8 (1001--):
Oh come now, Steve, you didn't honestly think I would let you get away with that, did you?
Ending 9 (1000--):
We had a deal, Steve. You could have gone off on your own, that wasn't a trick. Was my offer really not good enough?
Ending 10 (0-----):
I made this story for you, Steve. ALL you had to do was step into the hallway!
Additionally, there is a sign in the lounge (go right at the two doors) that says: "Remember: You are the key to a successful office environment." This indicates that the word "Steve" is important in each ending, specifically its location. By extracting the location of the word Steve from each ending and ordering by correct-ness (as shown above) solvers obtain the code:
By entering this code into the vault's keypad, solvers gain access to the vault's interior, which contains a chest with the answer inside: PINE.
There are cheat protections in place in the map so that solvers cannot easily obtain the answer before inputting the code, but these do not necessarily need explanation.