I have it and I even opened it!
I have not played it much but I can give some quick impressions. The graphics are done by the same group that did Odin Sphere, so the anime character designs are very well done and quite colorful. Actually, I think the look for both this game and Odin Sphere are quite fantastic. Basically, Grim Grimoire is a real time strategy game. The unusual aspect is that the "maps" are not top down perspective like common RTS games do. Instead, in GG they are side view areas, like you see in side scrolling arcade games. You create an army of units, explore the environment and fight enemies. I have not gotten too far into the game so unfortunately I can't comment on the overall difficulty of the game, but it definitely plays like an RTS game. The voice acting is decent (you can select English or Japanese).
I guess it comes down to whether or not you like an anime based RTS game.
