definitely good from an artistic point of view. Actually I just read the "artistic" classification of this so it makes more sense. The castle map is my favorite as far as details go. I was confused when I saw like 4 flags lol.
The space map is pretty basic. It coulda used more... depth.
The castle's my favorite as I said, mostly because of the detailed throne-like thing at one of the red castle's flags.
storage is okay. There was one area where I could jump onto the boxes but got stopped by clip which is bad for creating a realistic atmosphere (it was outside where the clip covers the whole top so you can't escape).
finally, deathmetal was pretty sick. I liked the teleport details, and it inspired me to design my own jumppads/teleport stations as opposed to just using mapmodels and stuff. it's more creative. Also you replaced the use of a wall lamp mapmodel with your custom cube one, which is cool.
All in all, 4 stars.. Individually these might get higher ratings (most are 5 but one is 4 so i can't give it 5*)
Great job guys, these maps will definitely be referred to in my maps just for "artistic inspiration" ;]