try to use intel HD GPU. seal online is a fairly old game and i remmember playing it with intel 965 GMA family chipset back in 2007. Now regarding this case, I ahvea GTX980M with 4GB VRAM and an INTEL HD4600 GPU from my I7 4720HQ processor, follow the guide on previous post regarding disabling DPI scaling. IMO, i can read my text better with INTEL HD 4600 GPU rather than my GTX980M GPU.
FOR MACBOOK PRO/MACBOOK USERS
you can play this on your system using BOOTCAMP and install on it. I tried on INTEL HD 4000 and you can play it too using that.(tested it with MB PRO MID 2012 both i5 and i7 version)