Game's not bad, most people have a nice discovery experience because the game is gorgeous (graphics and art), some mechanics are cool and kind of refreshing regarding latest MMO releases. There's also a lot of content to do (whether you like it or not) since the game has been released in 2014 in korea and had updates since then. Combat gameplay works with classes, combos and potions. There's no real trinity though and teamplay / combat interactions are limited compared to other MMOs.
The PvP mechanics are bad, the penalties prevent most of it unless you're at war with other guilds and PvP suffers from the gear > level > buffs > skill formula, depending of which class you play you're gonna one shot and / or get one shot a lot (castle sieges and ressource control is ingame tho, just not available yet). Low end PvE is what Malkav said, it's "gather all the mobs and AoE them", quests are very bland, lore is generic asian MMO crap and quite forgetable. "High" level PvE is bosses you summon with items farmed from daily quests, and there's world bosses as well.
If you have a MMO itch you can buy the game, it's $30 there's no sub and the cash shop isn't really P2W (careful though, some people seem to suffer from pet addiction, they purchase them like it's heroin). There's a lot of stuff to do and whilst some of it is mediocre, you might find your joy in other aspects of the game.