Oooh, now I'm gonna have to look for that! When I was first playing this level, I had to invoke my ancient secret-hunting powers of literally "using" every single suspicious wall panel that I could find, and I must have triggered that without realizing it!
Naturally, there are Doom ports on modern platforms like Android and iOS. Someone even made aDoom-themed live wallpaper. But those lack the double dose of nostalgia of playing the seminal first person shooter on a mobile phone barely fast enough to live up to the performance of an early 90...