First of all, Poke 646 is fuckin' A.
This mod is excellant, it's almost a Total Conversion, due to the amount changed, but not ALL is changed. It comes with it's own installer, it has MP3 soundtracks that can be played in-game and is a fearful ride throughout. Featuring new textures, new sounds, new models, new skins and best of all, new weapons! In Poke 646, you come across all sorts of notes and help throughout, something that is slowly coming into games such as AvP2. There is a scary train ride in which you have to climb out of a speeding train and head across the roof. Not to mention dodging the overhead obstacles!
You can see from the start, that the makers of this mod have been influenced by another brilliant scary mod - They Hunger, and this is clear, as in one point there is a cinema and it says 'Now showing They Hunger 4' above the door. The credits at the end are wicked, they look just like the credits at the end of a film. They scroll up and off the screen, with logos and websites as well. The ending is quite hard at first, as you have to dodge a robocop type 'boss'. Who, need I say is hard!
This game feels like Chemical Existence and the aforementioned They Hunger. There's just something there that makes it feel like you are playing CE or TH. I think it feels like CE because of your clumpy footsteps and CE was the first Total Conversion single player mod that I played, and this is the closest thing to it to date. It feels like TH because of the horror factor, it's not really scary, but there are dead civilians laying around with savage and gross injuries, like that of They Hunger. You won't be able to help but be amazed at the complexity and realness of the built-up areas. The buildings are perfectly textured and all together, they look like a real urban environment.
I mentioned new textures earlier didn't I? Yes, there are new textures, in fact ALL of the textures are new, not just some. They are also photo-realistic, like the ones in Max Payne, so I suppose that they are actual photos. There are some very well constructed vehicles throughout as well, you cannot drive them though. Note the excellant effect of the reflective flooring in the library entrance hall and rest areas.
Oh yeah, I nearly forgot. There is a good training course in Poke 646. This takes you through the things that you won't find in Half-Life. It points out the differences to what we're all used to and shows you how to use certain weapons and how to avoid and deal with the enemy. There is another thing that you may find a bit weird at first - Stamina. I don't think that it is affected by running or jumping (strangely), as I didn't encounter any problems. But, what it does affect is your melee weapon. In this case it is a section of radiator pipe. If you swing it about too much, you will tire and hear a panting sound. The amount of times you can swing the pipe and the damage you do with it will decrease. Wait a few seconds and it will restore. There is no stamina meter to see how affected you are, but it shouldn't be a problem.
All in all, a very good mod. Get it at all costs!