Fun little map! The keys were somewhat tricky, and the ending was harder than I expected in Nightmare, I should have proceeded through the map more carefully.

Played on Normal and NIghtmare did not notice much difference. Other than that, fine little offering.

Really nice little map. Enjoyable to work through, keeps you on your toes. Nice feeling of unlocking and opening things up, and briefly revisiting earlier spots or seeing them from a new angle.

The only thing I'd ding it for is that the entrance to the path to get the gold key, and then after that again the path to get the silver key, require the player to do something that really isn't explained/signalled. Fortunately the map is small enough that you can just run around trying all sorts of stuff, but it requires being confident that the mapper hasn't screwed up and softlocked you. In this case that trust is rewarded. :-)

Only one actual criticism which is that you may need to start the level with the player destroying a ventilation grating so we know that this is a possibility as I was running around in circles for a minute during the spot where it's required to continue, other than that, no complaints. Fantastic level and great escalation in threats.

(My specific recommendation is on future versions of this level, if you make one, start the character in a vent or very quickly requiring them to destroy one with a visible required component on the other side.)