Ridiculous development (In an end he didn't even have a reason to want to destroy the world, since he KNEW he wasn't an ancient), little screentime, Oedipus Complex, overall cliché anime villain, barely spoke to the party in general just to cloud, stupid design, didn't have any good dialogue nor any dialogue previous to the final battle, lack of any success whatsoever as a villain, etc.
And FF7's gameplay was killed by lack plot that made playing interesting and too much customization.