For a first map, this was really nice! I played it with the Alkaline mod (since it's a base level) and enjoyed it. Good job.
Yah this was cool. I really enjoy the theme variety and the indoor/outdoor/underground/water mix. The final secret was nice and cheeky too. :-)
I did kinda miss the grenade launcher, I know it would trivialize a couple of the fights at the end but that can be fun too! Maybe it was in the one secret I didn't find?
Great first map.