First off, I have to say, for a first map this is really very well-done and I do like it!
The feedback:
In general, the map is
far too overscaled. There's a ton of empty space that means decent snipers will become unstoppable. I'm pretty sure you must've playtested the map as Scout, because I don't want to imagine trying to waddle from point A to point B as Heavy (not to mention the Snipers).
In general, hallways in TF2 should be sized around 256 units in width at a minimum unless it's a vent. Stairs shouldn't be of a 1:1 height to length ratio. I recommend looking at Valve's maps and seeing how they handle units and space. More focused feedback:
- The HDR bloom is quite a bit too intense. For your alpha/beta releases, I'd recommend simply doing non-HDR compiles, and leaving the tweaking 'til the detailing stages.
I'm aware that this problem probably isn't your fault, and I don't know how to fix it myself, but I thought I may as well point it out. If it's not clear, the door prop is rendering on top of the respawnroom visualizer.
...Okay, these spotlit corridors actually look really cool, but in TF2 there should really never be any pitch-black areas. I'd recommend making these hallways lighter, with clearly defined spotlights (you can use a point_spotlight for lightbeams instead) and just make the darker areas in shade. Another thing is that long corridors don't really work in TF2, you could use their space as an opportunity to add staircases to link to the highground for better flow. I can see these corridors becoming spytech or industrial quite well, but they need to be shortened and made lighter.
This prop structure is actually pretty cool, and I can imagine having fun dodging and jumping around it. However, as it's surrounded by empty space, I don't think it's been placed with its full potential in mind.
This point is decent, but I don't think the capture volume should be anywhere except at the top, as it would be annoying for capturing people to have their progress halted by someone they can't see. Also, I think the walkways leading up are quite thin and precarious (also 1:1), but I guess the area around the point is made pretty cramped by the crates so it makes sense. Maybe lowering the point a bit would help.
Overall, good stuff for a first try! Keep at it, and keep us updated