My first map

This is the first real map I made, what you think?
http://www.mediafire.com/?sharekey=8fdd7b769bfaa7f5d2db6fb9a8902bda

From the offset can I just say that I am sorry but this is going to sound very scathing but these are just very stereotypical first map mistakes.

For starters the starting room is VERY bland and rather than two shotguns, wouldn't a shotgun and some shells have looked better. In the second room you come to the button on the opposite side of the pillar from the start room seemed to do nothing. In the third room I turned left past the marble face by pressing teh button, after killing everything inside I went in, the door closed and for the life of me I could find no way out other than jumping up as I was using zdoom. In the next room the bars glitched into the floor. ANd for goodness sake don't use commander keens, along with Wolfenstein SS they look so tacky. Not the worst first level ever by any means, infact not bad at all really but could do with some modification before it is worth uploading to the archive.