For a first time map, this was really good. I don't play TF2 so I had no idea what to expect in this map, but I enjoyed it. It was quite challenging but not impossible. My only quarrel, is the colored lighting. Colored is not a bad thing, but you really oversaturated them. You definitely want to consider toning them down ALOT for other releases.
I foresee great maps from you in the near future :)
First run demo, hard skill, played in Quakespasm:
http://qrf.servequake.com/~orl/misc/orl_gravelpit_demo.rar