It seems like they looked at WoW and though that they will be special by inverting everything.
Control with tank/heal/dps -> chaotic pvp-like fights
First dungeon extremely easy, increasing difficulty and mechanics as you progress -> first dungeon very hard from start, nothing to prepare people for it when soloing.
Thrash being 'break' between bosses -> thrash harder than some bosses they guard
Thrash always pull together, it's a group that is challenge you need to overcome -> can exploit mob leash to bring single mobs destroying supposed challenge
Hard hitting skills on mobs have long cast time, can and should be interrupted, have cooldown if successfull -> hard hitting skills instant, no way to tell if mob is going to wipe you with aoe or do autoattack, interrupt have no effect on skill CD and mob will cast it again
One life per encounter, wipe means reset -> Graveyard zerg
Bosses having cast bar and often rich voice acting in case of powerful attacks or mechanics -> one shot attacks often with no cue, or hidden behind particles
Very clear void zones, easily distinguishable apart from helpfull/team aoe even in 25 man raids -> small barely noticeable circles sometimes blending with terrain, easy to mistake for ally skill, even in 5 man drowning in special effects all over screen decreasing visibility
The only thing that they manage right is first point, the difference is refreshing in change of pace, rest is just terrible. In every single game, you die, you lose. Graveyard zerging should not be a valid tactic, ever! I would really like to have encounters closed to get back until group either wins or wipes, if only to shut up people saying difficulty is fine WHILE bum-rushing mobs to 'win'.
Trash mobs are together for a reason, you pull one, you pull all, point is to defeat whole group. Pulling one apart is pure exploiting weak mob AI. I hope they will improve that.
Insta kill abilities are fine IF they are clearly shown. Some mobs have 2-3 second windup on their attacks, if you stand in the it's your fault. Others like snipers in CM require you to spot a target circle under you are less fine, since it's just illusion of charging, if you don't notice it the moment it appears under your feet, you can't time dodge, and mob itself from what I seen just aim with no cues when it will pull trigger. Some just maul you instantly, with no chance to roll.
Void zones that are same color as arena you are fighting on. Foefire on King Adalberk is best example, light bluish small flames on a bluish floor, bonus point if you have blue-ish flame inducting Guardian in party.
Visuals in this game are great, but work completely against what ANet is trying to push (looking at mob, not his castbar, to know what is coming your way), they are all over the screen, to the point finding enemy in them seems more like Find Wally. I believe they said that they don't want addons in game so that you fight enemies, not ui, but currently, I'm not fighting enemies, I'm fighting with my teammates spells.
Camera not having ability to zoom out while you must watch for every mob yourself is... well, not bad design, but they aren't sticking to it. If you want to have limited PoV in game, you should not be able to rotate camera without rotating character, making looking around impossible if fighting a mob. That would be fine. But you can do that, yet somehow can't zoom it out to have better view on battlefield, so the most efficient way to play is tapping 'look behind key', getting dizzy irl, but having pretty much 360 degree fov. Just let me zoom out instead
Less damage from 'auto' attacks, keep one shots in but give better way to predict them, let me turn down others effect, more visible void zones, THEN disable ability to zerg rush (one live, one try) and you still have hard dungeons, but with less cheap effects and deaths that you can say was your fault every time.