Overall, Life or Death is a good game and definitely has a lot of potential to become greater. I love the permadeath feature but also find quite challenging with enemies being extremely punishing. All you have to do is get stuck in a small trap wall corner and that's it. Game over. Sometimes the attacking doesn't register either.
I also have problems with the repetition of each level, as I found that relatively boring having to go through several mazes to find the same key and have the enemies continuously ganging up on you. Also, you might need to make the key in the first maze prominent. I could not see the key at all and remained stuck for 10 more minutes. I did eventually find it, but I wished it was apparent and not color hidden.
Now for the lore bits, because I'm a lore enthusiast. I have so many questions regarding the world-building and how did you come up with the idea of the nightmare world and nightkillers? Note, I couldn't finish the game so I wouldn't know the ending, but it was a curious thought. How did the main character end up in the nightmare world? Why was he chosen? Small questions like these to make my mind going. On a side note, the only horror inducing element I found were the nightkillers since they sometimes spook you but overall, I did not find it as scary and the anxiety levels from the beginning drops later on. I found myself in annoyance in the later mazes instead. There may be more horror elements there, but I didn't find as "implemented effective" enough.
I find the music alright. I love the heartbeat sounds in the beginning and found that cool, but overall, it's pretty decent in the mazes and also a good indicator for when a nightkiller is nearby. Though, I would like to hear some screams from the nightkillers and more music variety. That goes the same with level designing, since the mazes are extremely large. I feel there can be more creativity within the nightmare world but hey, it's a start.
Cool and simplistic game. I like it.