The map size is not perfectly correct, it takes 2 minutes to complete, so in my opinion it's a small map.
You used dev textures, what ruins the atmosphere, altrough a few of the sounds in the map were spot on.
Lack of detail, boring and unrealistic style.
I found that very interesting if you break the crate that is needed to proceed, it explodes. I found it funny, but next time you should just set the crate to unbreakable :).
Overall: It's just needs more work man, I mean I hate when somebody relases something what's not finished, just for it to be up. I know I did it too and it didn't get nearly as much attention, if i'd done it. I'm sure i'd be proud of those maps today. Put more work in it and it'll pay off!
I'm not sure if you want to continue this mapping thing, but if yes, please do, you are on a good path I can tell you that!