I just played some Russian military mod of HL. The USA invades your counttry and you have to fight them back. Prepare to get heavily wrecked by the US army and their troops, light and medium tanks, and worst of all, the machine gun nests. I swear, those machine gun nests added at least 20 hours to the gametime since I didnt quicksave as often as I should have.
The mapping is alright as you can see in the screen shots, but what you dont see is that the mapping is actually extremely sloppy. Loads of areas to get stuck in and visual glitches. Instructions appear as on screen game_text and in some cases you have about 5 seconds to read it or fail to know what to do. Alot of doors are breakable(but they dont open) so if you dont whack every door you see you will get stuck too.
The mod contains all of the base op4 assets but I suspect the biggest reason the author used op4 is for the friendly soldiers.
I must say this mod is pretty unforgiving. Combat is very tough even with the op4 weapons in stock. There are many US soldiers coming and they wont hesitate to rush at u from any direction or hide in some dark area and ambush u. Expect every US soldier to carry grenades or noob tubes. And the worst is how they can see you perfectly from behind thick plants where you have no hope of seeing them. Same goes for the tanks. Did I mention the machine gun nests? They will reck u hard. They dont work like normal machine guns, they spray shotgun shells extremely fast from extra long range. Dont even THINK about rushing them or even picking at them from long range. You will have to be extremely careful. Not only can they take you to school at extra long range, they can actually bend at a 90° angle to spray you when you think you are save. And there's a random weaponstrip somewhere in the mod so don't bother saving ammo or whatever.
It says theres 2 endings, but really there's almost no difference between them. Basically one 'ending' will let you get to an extra level which I thought was unfinished, because nothing happens in it. And another map was about 2 seconds long. About 7 or so maps are copied due to the routes splitting between the two endings, but there are no differences between them.
Overall I think this mod is very different from you standard mod. If you are looking to get recked by US soldiers then this is the mod for you. It's difficult, but not impossible and you might make it to the end if you be careful and find a way thru.
(I wish someone would stream this mod so you can see how tough it is, lol)