Stunning, and fresh
When I bought this, I had the typical "expansion pack" (i.e. this is technically not an expansion) skepticism. Would it simply be more missions, areas, items, etc. and a gimmicks like alliances? Nope. This is another quality title which not only has the standard aforementioned add-ons, it brings so much more into the Guild Wars universe. The amazing thing about this game is how easy it is to pick up and play, but how deep the games systems go. A relatively casual gamer can pick up this title and enjoy it thouroughly, whereas hardcore gamers can really learn the inner workings of the game and compete in pvp that is probably (this is a bold statement) one of the deepest and best balanced of any online rpg ever.
The new gameplay features, which include alliance battles, new pvp modes, 2 opposing factions that players allie with, competetive missions, challenge missions, 2 new classes, and elite missions really breathes life into the game for gamers who were becoming sick of the original. There is much more high level content, which gives players better incentives to keep playing, whereas in Prophecies the options were basically limited to the Hall of Heroes, Guild Battles, and farming (trying to get that oh so wonderful fissure armor.)
The world itself is not as big as the original as far as land mass goes, which was kind of a bummer to me until I played it. This game takes much longer to complete than the original and there is much more content crammed into it than the original.
The game is also more difficult than the original, and the story missions more varied and interesting. In Prophecies pretty much every mission boiled down to get from point A to B and kill stuff. In Factions, you will find yourself protecting turtle convoys, fighting in 16 person parties against waves of dozens of enemies at once, defending objectives, and of course traveling from point A to B.
The story, I believe is much more intruiging than the original plot. However, the voice acting is pretty bad, with awkward pauses in dialogue and odd voices (Imagine the dragon Glint from the original). The music is good and suits the game well, although there will probably be no tunes here you will be listening to for your leisure listening.
The graphics are slightly improved over the original, it now supports newer shader models, but the only visual improvements I have noticed are higher polygon counts on screen, mainly the environments and some more interesting spell effects. Also, there are typically many more enemies and allies on screen at once than in the original.
In conclusion, if you liked the original at all, pick this up definitely if you are becoming sick of the content in the original, or just want to play some new stuff. If you are a fan of rpg's I would recommend this as well, although some people complain about the level cap, so if you prefer kiting for hours and hours to level up for months straigh, I wouldnt recommend this game. Its high points would be the great pvp, replayability, graphics, and fun and varied gameplay.