Return to Castle Wolfenstein
"Return to Castle Wolfenstein" received favorable reviews from critics. At Metacritic, it scores 88/100 (based on 32 reviews), and on GameRankings it scores 86.75% (based on 50 reviews). "Eurogamer"'s Tom Bramwell called "Return to Castle Wolfenstein" "a worthy addition to the stable of id Software affiliated shoot 'em ups. The single player game is average to good and takes quite a while to finish, but the game really earns its salt by shipping with a first class multiplayer element."
The Castles of Dr. Creep
A game enthusiast worked on a faithful game engine remake for the game since 2010 via reverse engineering, source code is on GitHub under the GPLv3. The remake got released on Steam by the original author and the remake author in September 2016. Available for PC (Windows, OS X, and Linux platform) it is sold for $2.99.