-Several areas lacked in a decent art pass, making some rooms look out of place.
-Although the layout is linear, the map didn't exactly give a sense of direction in some areas.
-The elevator panic event didn't give me any warning besides just music, and I didn't know what exactly to expect until it happened.
-The "Boss" fight (not exactly your fault.) is kinda uncreatively overused in most custom Black Mesa / Half-Life 2 maps.
-Backtracking, not to funnest thing to do if it isn't creativly altered to be interesting and/or challenging. Plus I wasn't exactly sure this is what I had to do after the heli boss fight due to lack of sense of direction provide by the map.
-Lots of visual bugs presented, such as clipping, visable nodraw areas and exploiting outside the map.

Sorry if this is harsh, I hope you'll take this criticism not in a negative way, but a way to improve this map, and/or all future projects. With that being said, I wish you luck on whatever you're doing next.