Now that I think about it more... I guess this game doesn't simply feel that special to me. Phantasy Star Zero is unique to me, because it's the closest thing to "3D Ds MMO", it's like a portable N64 MMO, which is really charming to me and it's propably the only of it's kind on the Ds. Blood of Bahamut's concept is quite unique too. You're fighting two things at the same time, one giant and lots of regular enemies and your goal is to attack different parts of the giant, there's just so much going on, that it feels much more special. Also, one thing I noticed those two game have that Soma Bringer doesn't, is dodging, which adds a lot into the combat. Rune Factory 3 doesn't have a dodging system, but combat is just one of the small things that game has to offer, so it's on a way another level.
So, even if Soma Bringer is a good game, it just doesn't feel unique enough to me and is just another hack and slash.