[English website] As you might have known now, the English server for RaiderZ is currently in Alpha test. Which means there will be glitches and some bugs, although quite a number swore not to have met any. The English server presumably is still not updated with the optimized graphics, which was added into the Korean server not too long ago (link).
As you can see in the new trailer above, there are quite a couple of new maps and epic bosses (otherwise known as BAMs, Big Ass Monsters) added into the Korean version. This is just the first step as publisher Neowiz Games prepare the title for Open Beta somewhere around summer. Read up my personal opinion of the game here (link)!