Man, talk about getting caught off guard by how much you enjoyed a game. (Partially because I played Persona 1 before it) I went into Soul Hackers expecting to like it but not love it, and I finished very much liking the game. The dungeons and combat I had fun with, the story (even if it isn't as deep as SMT and Persona) was a good time, and had some real good songs.
My only gripes would be the final boss (because it's two bosses with no save between), the inability to skip cutscenes (even on 3DS), and the flawed App system (in there's basically like 4 you'd wanna stick to for the rest of the game), but otherwise than that, I think this is a great time, and (speically given it's not very long and a bit easy) a great starting point to MegaTen...
Shame the only officially translated version (at least in the States) is the 3DS version, though.

(Played the XBLA version via Rare Replay)
Eeeehhhhh I didn't like this one very much. Music's catchy, it looks nice, I love the characters and humor, and I find Grunty's Lair a great hub world, but it feels like the game peaks in Spiral Mountain, Mumbo's Mountain and Treasure Trove Cove, and then just drops further and further as it goes on, the exception being Mad Monster Mansion, which I thought was pretty fun (if a bit annoying from the gravestones and dying, more on that later).
Alongside that, collecting can be really annoying at points, the swimming and flying controls aren't very good (even with the sharp turn), the mapping of Wonderwing (at least on XBLA) is a bit dumb, some enemies requiring Wonderwing to be killed is dumb, having to go from the entrance back to wherever world you were at/going to when you reload a save gets annoying when you start getting to the later levels, the spamming of the hole enemies (especially on small platforms, usually leading you to falling off if they hit you) is annoying, the lives system is very dumb (though tbf, lives systems in collectathons in general is very dumb and shouldn't be a thing and (in the XBLA version) the only way to circumvent it disables saving, dying is a pain in the ass because it resets almost everything in the level, the lack of a reticle makes egg shooting and the beak bomb annoying to work with, and the fixed camera angles can obscure important things or screw you over.

(despite all the negative things I said) I don't think it's at all a bad game, but I don't think it's great either, and it's one I don't think I'm gonna want to come back to anytime soon.

Oh yeah also the last two phases of the final boss are horseshit.

What happens when a pretentious man who can't write for shit gets out a pot, puts in every random moment and idea that came to mind (which all could work if fleshed out more but no), "immersion" and film things that shouldn't be game things, a stupid belief that game overs (in story based games) are a failure of the game designer, and a bunch of other dumb things, stirs it into a hard to understand, incoherent mess, and throws it in an oven preheated to 375° for what's apparently 10 hours but feels like 10 years?

You get Beyond: Two Souls, a boring mess of a "game" with a story I could barely follow and lost all care for, has no tension because you can't die, has frustrating QTEs where rather than the game telling you which way to move the right stick, it instead makes you figure out that in 3 seconds through the characters (90% of the time being really hard to tell), and ended with me just giving up on it from how bad it is, and really just wanting to skip Detroit: Become Human and end the Cage-trilogy here.

Legit the only good thing about this game is the music and nothing else.

Don't play this.