So, I've played the map yesterday on Nightmare difficulty, I still need to test it on Classic, so I will update this when I do. However, most of the feedback applies to both difficulties. Overall I liked the map, it has logical objectives, a good mix of open and closed areas, geometry is nice, good displacements. I wish the outdoor forest section would appear again in the middle of the map or at the end, but it's fine.

Here's the list of the stuff that I would change:

- Most objective glows use only one color when there are several objective items involved, like the battery/gascan objective. The gascan and battery should have a red color and the generator should have a white color like in most objective maps. Additionally, the color you chose for most items is a very muted grey color, it can make seeing the items you must use difficult. You should change it to white.

- The map lacks anti-objectives or objective RNG, meaning different routes and objectives the players must complete which are selected randomly at the start of the round. Adding more random paths and item spawn points should increase the difficulty, variety and replay value.

- Shambler spawn density is generally fine, but you should add a bit more runners to most sections, since they can be completed without much hassle.

- Some zombie spawn brushes respawn zombies when you are way too close to them. This results in groups of 10 zombies spawning out of thin air in front of your face. Maybe reworking them so that they only spawn when players aren't looking, or force them to spawn zombies even when players are a good distance away.

- Most doors keep closing on contact with a zombie or player, making them extremely annoying to go through, they should only respond to player or zombie interaction (manually opening them), they shouldn't change their movement direction when they touch something.

- This is related to the last item, but the fence that needs to be welded has the exact same problem, and I've had zombies get stuck on it while half open, causing a softlock, since the team lacked ammunition and there was no way to attack the zombie behind the fence.

- The fuses you find inside the boxes in the warehouse don't have any glows, I suggest adding a red glow to each one, since that section has limited lighting.

- I suggest that the fuses should spawn on the ground, they currently spawn in the air and fall down to the floor

- The warehouse's doors are way too loud when they open, as if the sound effects are stacking and increasing the volume

- The key found on the corpse after going up the elevator should have a keychain that corresponds to the door or padlock that it unlocks, since it doesn't have any type of glow

- Like others mentioned, lighting does need a rework. The map itself is not that dark honestly, I didn't have much trouble finding my way, but the lights do look a bit muted, they don't look realistic. Check nmo_cleopas or nmo_quarantine since they have very good lighting overall

- The map lacks reflections. Like Porkchops mentioned, you need to build the cubemaps.

- I haven't fully tested the clips, but I did notice a lack of Vphysclips around the map. This will allow trolls to softlock the map by throwing objective items out of bounds. I'll send screenshots of this when I have some time.

- There are no player respawns in the entire map. Maybe this is intentional, but I think there should be at least one. On Nightmare difficulty, players tend to die very easily, so having one respawn will help the map be less tedious. Remember to spawn players in a closed off room or building.

- The sewer section should be much darker and eerie. Also, as much as I love HL1 sounds, you should replace the alarm that triggers when you turn on the turbine to something more realistic.

- The alarm should maybe trigger a few runner spawns to scare players and provide a bit more challenge.

- The model used for the rocket that you need to place inside the tank should be changed to the HL2 RPG rocket model.

- The final objective should be reworked entirely. You can cheese it very easily by kiting all runners around the chopper until the escape triggers. If you're playing with a team, this is no longer viable if all players want to survive because of the limited space for all 8 players to kite. This doesn't reward cooperation. Additionally, on Classic it looks like it would be trivial as long as a few players have machetes. On Nightmare, you're pretty much forced to kite, which means that there will be no cooperation in that last part.

My suggestion is to remove the infinite runner spam, too many maps already use that same boring and uninspired finale. You should create an item-based objective that requires cooperation. Runners should maybe spawn once or twice to provide some temporal challenge, they shouldn't respawn, and the true difficulty should be centered around what the players must do to refuel the chopper (maybe remove the chopper refueling, reparing radio equipment, plus turning on electricity in order to call a chopper would make more sense if you want to create an item-based objective). You should take a look at nmo_subside_v5's finale for some inspiration.

Overall, the map is looking very good for an early version and for being your first map. I suggest you focus your efforts on fixing, improving, re-balancing and detailing it until most issues are resolved. It should help you significantly when you move to further projects. I'll keep providing feedback as you release future updates.

Thanks again for taking the time to create this!