I played it when it first came out. Really enjoyed it, but the fact that the game was maassively unbalanced really put me off it.
IE: The marines could build these powerful sentries, and the aliens could build some that did almost no damage.
Now it's apparently pretty even, but playing it the other day, it is'nt that much better.
I'd still pick marine over alien any day. Guns > Teeth/dodgy slimey stuff.
Apart from all that negativity, it has to be handed to them, what they have made the original Half-Life look like. Some of the maps looks a lot better then the ones in AVP, which were specially made for the whole Humans Vs. Xenophone setting .
I liked it a lot. When it first came out, there seemed to be quite a lot of lag, even on UK servers (Which are pretty close to me, since i live in England). They managed to do a lot with the engine. I think one really innovative (Well kind of, because its been attempted before) feature, was the commanders overhead view. They pulled that off really well.
The balancing issues were a slight problem, but an organised group of aliens could take out the marines. It depends on who gets their act together the quickest. If the aliens managed to claim a second hive at the start, that gave them a real advantage over the marines.
They modified the engine a fair bit. I think, they even worked on the map sizes, actually increasing how big maps can be.
That mod certainly shows what can be done with a bit of work.
The potential it has is intense. I just hope they start working on some sort of project for NS on HL2, because that will completely bring the mod into it's own.
The reason for this is that I do feel it is somewhat held back by the age of the current engine they are using with it (Original HL/Quake warez). That's not to say they have not worked wonders and managed to bend all the rules
NS in source would be an amazing game. So long as they put as much work into it as the first, and didn't rely on the nice looking engine to carry them through. The level of detail in the models of NS is already high, imagine if they did the same with Hl2 and even improved on the Hl2 models. They could even introduce new elements to maps. Such as flying aliens and some kind of marine transports/attack craft. If not those then certainly some ground vehicles
With the new flexibility with vehicles with HL2, we could be looking at something to take on Tribes in the sense vehicles that can actually move in more than linear styles
I can't wait for the NS dev team to officially announce that they will be working on the modification for HL2.