Alrighty:

Combat is weird. In games like WoW its very smooth and well paced but in Aion it feels like theres a bit of delay between pressing an action key and actually hitting your enemy. It just feels slow and clunky.

The major selling point of the game was flying and flight combat. However they implemented both of these systems VERY poorly. Flight initially has a 60 second timer which gets only slightly better with new wings. However you don't gain the wings through levelling, you have to BUY them. Which is just strange, the wings should be part of your character, this just felt like any other MMORPG where you bought flying mounts however the mounts only lasted a few minutes at best. To top it off, you can only fly in very few select zones due to this weird tidbit in the lore about needing "divine energy" in the air to manifest your wings.

So they have an explanation for the time limit, which is great, in the explanation they say that in the gap between worlds (I think its called the abyss I can't remember) there is a huge concentration of divine energy because thats where its all draining into so manifesting your wings permanently is possible.

But the game mechanics don't reflect that, there is STILL a timer on flight, making flight combat a timed event and just butchering the concept entirely. The fact that they tried to sell their MMORPG as one big on flying whereever you want and fighting while flying is nothing short of sickening due to how they implemented it.

And finally the grind. There are very few quests in this game such that after a certain point you will be almost entirely focusing on killing mobs to level. I don't play MMORPGs for grind like that, and unlike an MMO like runescape where the grind can feel relatively rewarding, AIONs grinding just feels really slow with minimal reward.

TL;DR

Shitty combat

Shitty flight mechanic inconsistent with lore

Shitty grind.