Awesome concept carried out decently. The combat is good and is mostly fluid, and PvP is a lot of fun. The quests can get a bit dull, but they break the regular MMO grind by throwing in boss fights every few missions and lots of rewards for exploration and story completion. The story itself is decent enough, especially in Gotham where you take on Bane and Scarecrow. The only major flaw in the story is the HORRENDOUS voice acting for the Brainiac characters and most of the cops in the nightclubs and police stations. The voice acting on those characters is so laughably awful it completely breaks immersion and sometimes actually makes me laugh aloud. However I will say that the voice acting on the hero and villain NPCs (Joker, Superman, etc.) is fantastic. It's really awesome to fight alongside Batwoman to take down Scarecrow, or Superman to take down the Brainiac horde. There are also some annoying things that should be addressed:
1) When flying/running near enemies, if they attack you just once it slows your movement speed drastically, making navigating the city below the rooftops nearly impossible.
2) Sometimes stun abilities just won't work on certain enemies with no explanation as to why. There was a boss fight in which we fought Power Girl and she was regular size, no outstanding special abilities, but was completely immune to being stunned or knocked down, which was annoying because my character was control and that's the entire point of my build.
3) The flow of melee attacks can be awkward at times, mostly due to desync between players.
4) Enemies that have stun and knockdown use it CONSTANTLY, and you have to sit there spamming shift to get out of it.
Overall I give the game 7.5 out of 10, and would give it an 8 if they patched some of the player desync issues.
ALSO, forgot to mention, the game has a decent community and a lot of older players are helpful to new players.