If I had to put it into a few words, the recent "Once only" Lost Shores event for Guild Wars 2 was interesting, difficult and buggy. Not to be outclassed by the plethora of world events that litter the environment normally, especially at end game, ArenaNet obviously decided that it needed to pull out all the stops and provide something a little more unique and interactive, with an invasion that threatened to change the environment if not countered, coupled with new dungeon and PVP content. So I got up at 5am on the first day, hopped into my main and teleported to the source of the initial disturbance.
The event starts with what can only be described as a display of overwhelming force by the Karka, a race of giant enemy crabs intent on ditching their original sea floor environment for something a little more ground-based. It's an understatement to say that there were a lot of them, wave after wave pummeled some of the servers finest as we held our ground, lower level players dropping left, right and centre. The MotherCrabs, as I called them, rolled back and forth across the area, knocking unsuspecting players off their feet, while their younger brethren spam the crowd with all sorts of nasty AOE effects.
It was intense to say the least, especially if you were around to see them crawl out of the ocean in the first place -- while (obviously) scripted, it was pretty amazing to see them inflict permanent destruction on the normally static environment around us. It's intriguing that Blizzard didn't implement a similar situation when Cataclysm was released; imagine being there when Deathwing and his cronies flattened the continent, the whole server fighting in vain to push them back. While this event was obviously on a much smaller scale, it did provide that feeling of true dread and duty to defend your home.
What happens next is actually pretty intriguing. After you follow some NPCs to effectively "finish the job", you find out that the reason they came out in the first place is due to a plan to develop the island for tourists, forcing a relocation by the Karka into Lions Arch. Once the conspiracy is unveiled, there are some sequences where information is attempted to be dug out of the "consortium" (as they call themselves) about the Karka that they're not willing to tell. Eventually, you find yourself smashing through more elite crabs in their HQ, working up to the final boss - the "Ancient Karka"; obviously the person naming mobs at ArenaNet had run out of creative names for bosses.
I enjoyed this fight primarily due to the creative stage-based nature of its evolution. In one section, you are moving boulders into Steam-filled vents or felling large trees to blow off the top layer of the beast's impenetrable armour. In another, slogging through more waves of smaller mobs before eventually hitting that sweet spot where everyone is fighting tooth and nail during the final push, utilising GW2's loose grouping system to good measure via properly buffing the group and covering weaker characters.
But it wasn't a smooth experience from the beginning; bugs ranging from quests that wouldn't load correctly to NPCs so overwhelmed with requests they would stop responding. Quite a few times, most of my group were pushed temporarily into overflow servers, where everything continued to lag like crazy. This was primarily in Phase One, however, and while Phase Two started later than it should, things were much smoother, although I still found a lot of combat lag and times where enemies were bugged or clipping into the environment. By the time I hit the final boss, however, things had levelled out to a much more playable state.
ArenaNet deserve praise for attempting one-off events like these, especially since MMO players have been crying for unique, world-changing dynamic content for years. Bugs aside, there are quite a few lessons to be learnt, particularly in regards to how quests and content for such a large group of players is delivered, and possibly if these events could be repeated for those who missed out. But the sheer scale and interactivity is refreshing, especially when previous games have preferred to simply avoid making world changes open to player impact at all.
I haven't yet had the ability to try out the PVP or Dungeon content as yet, but I invite you to share your own experiences in the comments.