Really glad to have found this game when I was just simply browsing itch.io.
Great game! Reminds me a lot of games such as Quake II, especially the shotgun. The game is also not that easy for me, but I really like that I have to choose my approach wisely according to the ammo I have. Taking risk to explore new areas is also exciting, due to the punishment of starting all over again if I die. However I still really hope for a checkpoint system because that punishment can be too great.
I like the map which is interconnected and "multi-layered", means I can always find ways to go higher and get over some obstacles. Its "semi-openness" also reminds me a little of the Kshatriya level in the game Metro. I found some floppy-disk like stuffs but don't know what they do. Also I have climbed high enough and it seems there are places where I may fall off the map, although I didn't dare to try.
Anyway, I'm eager to see more of this.