I do not recall ever playing this when it was a DOS game - and I truly thought I had played just about every early FPS type game there was back then. I enjoyed playing this for the most part, it seems to be a technically well put together updated remake. But it is more of a Wolf3d maze with hidden doors and puzzles. It really throws you for a loop and kills you instantly many times, so do save the game a lot. One level actually starts with your character in boiling lava, so by the time you figure that out, you're already dead. And the puzzles are not very intuitive. I finally just gave up and uninstalled it. Maybe I did play this "back then" and just don't remember - it is very forgettable.