I just don't think Graal likes something about the Galaxy phones. I had the Graal app on my OLD android phone, the HTC EVO Shift, and Graal ran great on that. Even in Graal City I experienced very little slowdown.
However, I switched over to the Galaxy S2 and noticed a huge drop in performance. I don't know if it's Graal, or the hardware, but it's pretty obvious. It may be the huge jump in resolution, I dunno.