Here is a short summary of my first impressions of DK Online:

Graphics:  Although the ground textures are somewhat bland, the character models are very much on par with Raiderz.  The sky looked especially nice.  The overall feel of the graphics were very standard for a F2P mmorpg released nowadays.

Combat: Athought at low level, it is a traditional tab-target feel.  Throughout the first few levels I only learned a two skills over and above auto attack, but they really weren't needed.  It felt very "Lineage II 'esque"

Movement: Character movement is a bit clunky, but the worst part about movement is the invisible walls and impassable streams.  For an MMO to release in 2012 with such limited enviroments is a shame.  This may have been excusable in 2005, but for today's games, you need to be able to hop accoss that tiny stream to get to your quest mob on the other side.  To simply run into an invisible wall or a stream that just leaves you 'stuck' is a huge disappointment.  It was enough to convince me that this game isn't for me.

Questing: Standard "!" "?" questing.  It's familiar.

I did not have a chance to experience guild systems or pvp.

All in all, my first impression was less than stellar with the invisible walls and clunky character movement . Obviously if they fix these issues before full release, I may change my opinion.  

My first impressions on DK Online.

-Nice graphics for a F2P game.

-Point and click combat, few skills, few classes, all skills I had access to as a fighter were glorified auto attacks, and as mage skills were summons and generic fireballs.

-Standard mmo stuff we are all used to, spawn in the middle of nowhere, go kill local fauna.

-Quests: Kill ten rats.

-Almost no character customization.

-As user above said, see that huge expanse of terrain  that's looks like you can totally walk over there? Nope, have an invisible wall in the middle of a field. Also, want to jump down on that ledge to catch up with your party? Nope, go walk the way around.

My final opinion, if you can stand the graphics of lineage 2, then you are much better off playing lineage 2, and I don't even play lineage 2 anymore myself.

I was looking forward to this game and sadly very disappointed with what they offer, the game reminds me of something released 10 years ago not a new release. 

- The afore mentioned invisible walls in open terrain,

- click to move that can't be disabled,

- no mouse support beyond left and right click and unable to link to controls (no 2 button autorun),

- terrible skill trees that offer useless skills that have to be bought (skill points) before moving on to something useful,

- the pvp system is optional and severe penaties for killing someone,

- death penalty of 5% and possible item drop (for anyone who's played these grinders knows 5% could be a day to a week of grinding)

- small inventories that will be almost half full with equiped items (yes equiped gear stays in your bag)

There are more issues but these are enough to stop me from playing, I'm sure some things could be fixed but I doubt that the devs will fix any of these issues if they released it to CBT with the game as is.

This game is your typical Korean PvP-centric grinder. There's little to no innovation to the formula you've been used to for years and years. Other issues, beside the aforementioned:

1) Skil tree point wastage. You have to invest a point (sometimes two, to meet requirements for certain skills) in an utterly useless skill in order to meet reqs to get newer skills down the path. And some of the skills that are in one tree should be in the other tree. Oh, only two trees. One PvE oriented and the other PvP oriented.

2) A lack of a true melee ranged class/assassin-esque class. This could possibly come down the pipe later in the game's life cycle in the form of an expansion, but that's left to be seen. For now, if you prefer a ranged class, you're going to be a caster. No choice in the matter.

3) No progressive stat gain. When you level, you're given one, one point in which you can assign to one of five stats: STR, CON, AGI, INT, and WIS. As far as I can see, your other stats don't progress as you level. So if your character starts with 6 WIS, 20 levels down the line you're still going to have 6 WIS. This is a problem for caster classes, who may assign points primarily to INT for damage, but need secondary stat progression in WIS for mana. You can increase stats through runes tha can be socketed into armor and weapons, but runes are rare and socketing is very expensive.

4) Gender-lock. This may or may not be a deal breaker for some, as there are several games that employ this, but this has always nagged at me. Want to be a male caster? NO! Casting's a woman's job, man! Go and be a fighter! Ladies, want to roll a paladin? Faithless female heathen, go do some casting! And there are also classes that are tied to a specific race. But again, this may not make a big difference to you.