I thought the areas were rather bland, being just one room with a door or a small window doesn't really want me to progress further into the game. Try to add more detail into the rooms. Also, check your misaligned textures, as I spot a few, as well as some common mistakes (lower unpeg the door tracks) And one final thing, either get rid of some zombies or add more items. I suggest both. You went a little insane with the zombies later in the levels.
This is obviously one of your first wads, but I suggest not working on a project for now and just keep practicing and taking my advice.