MU Legend CBT 1: Missing Auction House
The core components for a rock solid ARPG are all here with the only really big mistake being the omission of some sort of Auction House/Trading system.
The most important feature that's missing from MuL is an Auction House. Using chat channels to trade within this game is ridiculous. Webzen should have known better than to plan a game like this without such a feature. I hope they add some form of in-game trading system (such as an auction house or personal store) before release. If they don't, it'll probably be the #1 complaint (and already is in the CBT forums). Items don't auto-stack when you put them in storage. Needs to be added. The Pet system is very confusing to players since one cannot get points until max level when pets can be acquired from the garden and then released. The very design of having to release (lose) pets in order to get points to level pets is just a bad design that people won't "get" at first. The voice acting and scripting for many of the quests is really, really bad.
There is a 64 (or so) character limit when texting in any channel or sending whispers to other players. This limitation is frustrating and prevents good communication, especially through whispers. The game doesn't share the friends list between characters. The game allows the players to skip quest/cutscene events that aren't core storyline, but forces players to watch storyline events. Need to be able to skip everything. Pressing ENTER responds to the last whisper instead of sending a whisper to the last person sent to. This can be a big problem when you're talking with a player and somebody else whispers you during the middle of the conversation. You can receive duel requests from other players while in combat, which can interfere with things. Storage containers are quite a distance from merchants that dismantle, requiring players to run all over town to deposit and manage their materials.
I greatly look forward to the next testing phase of MU Legend and I will definitely be playing the game at launch.