Beyond Castle Wolfenstein is the sequel to Castle Wolfenstein, the action-adventure known as the first stealth game. It was created by Muse Software, initially for the Commodore 64 and Apple II in 1984 (3 years after the original Castle Wolfenstein); it was ported to PC Booter in 1985.
Your mission is to infiltrate a Nazi bunker to plant a bomb outside the door of Hitler's office and escape before the bomb explodes. The graphics, very rudimentary, is definitely not the best aspect of this game, but the gameplay is great. You will have to stay hidden and avoid shooting as much as possible because if the guards activate the alarm, you will probably get caught. The dagger is the best choice if killing is necessary. Each level has a passcode that you can obtain by bribing the guards if you have enough money.
Thanks to the Beyond Castle Wolfenstein Project, we can now play the original PC Booter game on DOSBox, with speed adjusted and other minor fixes.