Ah, my apologies - that's how you're intended to get it. I misread your original message. I might change it up to make it more visible and prevent accidental cheese/not triggering the secret. I'm willing to bet it was one of those speedrunner "grab items through walls" things that only works when you're going a certain speed and direction.
Fixed for the next release, thank you!
EDIT #2: In MAP05, three Hell Knights waiting in the third hidden row at the bottom of the map seem unable to teleport in, even after having been activated.
Can't recreate this one. Which port/complevel are you using? That might help me figure out what's going on.
Never mind, figured it out. Teleport destination was misplaced in the version of the wad in the archive.
In any case, the music is pretty good, even if it does not always fit the mood of the map - which to be fair is something vanilla Doom is equally as guilty, so that is not really a criticism.
You seem to be quite talented as a composer!

Thanks for the feedback! My approach to the music was definitely similar to how the tracks were made in the original Doom - everything, in fact, is meant to be a bit reminiscent of the original experience, including having a variety of music that doesn't necessarily intend to reflect the map being played but just accompany the action (but some tracks do - see MAP04)
EDIT: I've updated the download to have fixes for the double secret in MAP04 and the Hell Knight not spawning in MAP05.