Normally I'm against fighting in close quarters, but I'm pleased that this map doesn't confine you to only tight corridors. There's always a wide area afterwards that you can breathe in as you reload and dodge the infected. Weapons and ammo will spawn in places where you really need them and they're always visible. Don't worry about stingy resources - you'll never run out of ammo provided you aren't a waster.

The lab gave me Black Mesa-esque vibes, especially that one area of the facility that's covered in what I assume is neurotoxin. There's even that one section where you have to cross pipes to get to the locked room. It reminded me a lot of Half-Life.

For the finale, it's your usual "run to the LZ!" moment. However, with the campaign's premise, it gave me a heroic feeling of rushing through hordes of zombies without looking back. The finale area isn't claustrophobic and you'll come across barrels that you can explode to aid clearing the horde.

For the horde themselves, they spawn in set locations. Meaning you don't have to give yourself whiplash going back and forth because they spawn everywhere. Special Infected, along with the commons, spawn within a reasonable distance - there's no need to worry of an SI magically appearing in front of you in thin air.

Even on Expert, I never had any problems nor frustrations on dealing with everyone. What a solid campaign! Its ratings are well-deserved.

Oh, by the way, download the campaign from here instead. It fixes the issues of Map 2 (crashes on loading).