>>1832089
Well, alright!
You have a handle on mapping, but there's some "quirks" that I'd like to point out. These could easily become part of your mapping "style" but are things people don't generally do, which in turn kind of makes your map seem like it doesn't "belong."
-Cardinal Romero-breaking rule: "If the player can see outside, make sure there's a way to get there." Obviously you can just jump out the window but considering the map is otherwise vanilla-compatible and there's no way to get back in (or out) without jumping, it's...not a great idea. Mark the window lines as Impassible, and add a real way to reach outside.
-Similarly, I don't really like to put enemies that drop ammo or weapons in places the player can't reach them; I'd replace them with Imps since this is obviously a Map01
-A LOT of enemies wake up when you first shoot, and suddenly become active and start swarming the player. Consider making some of them deaf.
-Similarly, your monster closets are really telegraphed; they seem to come through these SUPPORT2 doors which don't look really good. Similarly, I don't really like mixing SUPPORT3 in with techbase textures but there's no reason you can't do it.
-Plus, lots of little rooms seem to exist for the sole purpose of having monsters in them, and nothing else. Instead of building the level around little hallways with little rooms, in the future consider making larger rooms (separated and connected with smaller rooms and hallways) that have non-orthogonal (read: not square or rectangular) shapes, with lots of height variation.
-In fact, the level has almost no height variation at all; everything is the same basic hallway shape. Plus, I REALLY don't recommend using the same floor texture throughout most of a level--change it up between room themes, the tan STARTAN can use the tan variation of the floor texture you have. Don't forget to change the floor height (even if only by 8 or 16) when you change floor textures.