This game is most enjoyable by Guilty Gear fans. The game is very easy to pick up by those who haven't even played Guilty Gear. GG2O takes form of a Hack n Slash rather than a fighting game and at the same time involves simple strategy. I recommend this game to anyone who enjoys hack n slash.
The only cons to the game are the characters. Due to lack of characters from the previous GG series, is quite a let down to the fans, instead this game introduces new characters and enemies.
I believe this game deserves credit for the entire story. If you liked games like Dynasty Warriors, Dynasty Warriors: Gundam, then try out this game! It doesn't have as much hack n slash, but it has a better story line in comparison to DW :) Finally, this game is NOT a keeper. In my own experience this game is just good for rent, try it :D