This unusual game is given far too much bad publicity for its merits, its only true flaw being a lack of content.
Unlike most MMOs, there are no direct parallels to stereotypical classes, perhaps save for the sentinels as the damage dealers, or damage takers. Also unlike some other MMOs, there is gear that may be obtained that gives the player abilities that resemble the concept of a class, but are not restricted to a certain class unto itself, instead being tied to the gear that is equipped, like other class abilities.
However, the game has two outstanding flaws. The first, is a lack of content. Being a new game, the game world only has four major areas, a tutorial area and a side area, although there is quite a bit of interaction stuffed into these smaller worlds, not unlike the previous games that LEGO has been involved in.
The second major flaw is the lack of a team system. Instead, the game relies on an ad-hoc cooperation system, leaving little distinction between friendly help and a kill-stealer, the rewards, unfortunately, going to the player that strikes the last blow.
Also, there is a minor annoyance that is distinctly worth mentioning, the inability to send a number across chat. This is presumably in place to prevent younger players from revealing their age, but the circumvention of the system through words such as, "Tree" replacing, "Three" or "Sven" replacing, "Seven" can seem a bit ridiculous at times.
One system that may be disappointing, is the concept of home lots. Lots are available for free building, using bricks obtained in the main world through exploration, battle, and simple purchase. However, these lots are the only place where you can freely build, and show your creations to other people. There is barely any customization of models, such as cars (used for the racing minigame) or rockets (used for transportation between larger worlds) in the main world, and the area given for customization essentially limits your character to semi-functional buildings, stationary vehicles, or somewhat reactive creatures. If several people are in constant interaction with each other, and thus, experience the creations that others have made, the game's longevity may increase significantly between major content updates, as it appears as though there is no limit to the variety of pieces found within the game, though you may only carry so many types at any given time.
While it does have its merits right now, unless you are looking for a distinctively different experience, as some games targeted at a younger demographic offer, it may be more prudent to buy a game from the traveler's tales series, as opposed to buying this, as enjoyment of this game appears to largely be a matter of personal taste, especially at this time when you are paying $40 for a game with four major worlds, including a hub world.