Join an assault on a Combine outpost, and help the resistance prevail.
For the most part a really well designed mod.
Here are some of my thoughts:
1. Alarm at the beginning when you press the button cannot be really heard, because of the music.
2. Turrets are deactivated after the player walks past them for no reason.
3. The player gets to fight Combine Soldiers before getting a good weapon. This is done fairly lightly here as you get a shotgun just after that, but you have to be very careful with this. In HL2 you got a Revolver to fight Metropolice SMG units and by the time you meet Combine Soldiers, you already have a Revolver, a Shotgun and a Gravity Gun.
In your mod you don't have any of these at this point, so this could easily lead to bullet sponge enemies, however you've included 2 barrels to help the player with the task, this is great, but they're placed in a weird spot exposing the player to a lot damage, before he can even set them up.
4. "Lambda" door opens instantly after killing the sniper, add a little delay to make it more natural.
5. Skybox areas are too open, dev textures are visible when you noclip outside of the map, this is not needed after the mod's release. Just replace them with NODRAWs, Hammer has a tool to do that in a few seconds. I have a good PC so this is not a problem for me, but I'm pretty sure a lot of people are going to be grateful for this.
My favourite parts of the mod:
1. Difficulty - I've played it on hard and the mod felt fairly well balanced. I never run out medkits, armor or ammo, yet there was never plenty of it.
2. Atmosphere (for the most part).
3. First guardian fight. Nailed the atmosphere. Especially the lighting and choice of music.
4. Barancle / rotor room after raising up the water, great atmosphere, some fake volumetric lighting (sprites / glows etc.) would make this look even better.
Btw I recommend instructing people to install non-standalone mods like these into for example: "ep2/custom/[modname]/maps" instead of "ep2/maps", so that it doesn't bloat their main game files.
"[modname]" in this case is just a random name for content, I've used "city25" this time and it worked for me.
Or just create it into a standalone sourcemod formula.