I only played two of their games. the 3DS one (Burst) and Shinovi Versus. The 3DS game sold me on the characters, not just the good guys, but the "bad guys" as well, even though parts of their story was a copy/paste of the hero story (e.g. the card game on the boat scene), but it gave you a reason to care about them because they had a fucked up past and no one else would take them in, especially the "good" side, where they are so anally strict that they ban you for the most mundane shit. Was disappointed on the anime though, specifically the ending. It isn't exactly canon to how the true ending is for the game. Also I think it was censored, but then again I got the Funimation DVD/Blu-Ray combo, so that might be why.
The second game I wasn't entirely sold on, both story and gameplay. I know in one of their mobile games they have like a bajillion characters, so it's probably hard to keep up with the series up to that point.