Wait.. Dark Castle actually runs?!
I can't get the controls to work, can anyone help.. I desperately want to show this to my son so he can see what I used to play. :)
Not sure for PC or Linux, but the keyboard works in the newest Chrome on my older Intel Mac Mini. I just had to go to Apple -> Control Panels -> Monitors -> scroll up -> Black & White before launching. For new players, the keys are under the Options button at lower-right: AWDS (move), Q (action), E (duck), Space (jump), using the mouse to aim the arm up and down and clicking to shoot. The Info button explains: keys 1-4 to choose the door in the beginning, Tab (pause) and Command-Q (quit, but quits the browser..), some keys can be held down.. good luck!