Here are some things I've noticed so far.
1) If you use Iron Case, kiss EVERYTHING goodbye, including cash shop items. They're gone. (correction: apparently not all are bugged, but many)
2) ALL classes look like retarded planks, cleric lower body no longer move, they glide. (correction: lower body bugged only at certain times)
3) Many users trapped in maps, and cannot teleport or will die/crash.
4) Attack motion bugged for all, weird gaps in between skills.
5) Tomb of Helga mobs 1 hit ko my friend with 2000+ defense. (from outside source Helga is said to be a level 100+ mob)
6) Dark Passage barely have any mobs, in sharp contrast to Outspark "great hunting grounds" statement.
7) Mini Dragon Hardcore is 45-60, with 70 difficulty (or so as I've heard); GL to those that join. (from personally testing this KQ is way too easy)
8) Many mobs run funny as well (take KM for example).
9) When attacking...... guy clerics make girl noises....
10) When using invincible, wings go to the other person.
11) Archer chestplates "puff" when running.
Also to mages: use your *insert fireworks* BRAND NEW "FIXED & IMPROVISED" mana burn...... you will get a really good laugh, perhaps save it for when you are angry (not from the above bugs however).
That's what I've noticed in a few short minutes, I am too angry to try to find out more, not that I can since I'm trapped LMAO.