Dropping a well thought out visual aesthetic in favor of one that "tested better". I'm looking at you Golden Sun. The quasi-claymation players and enemies with stretching and warping sprites gave the first two games such a nice storybook feel. The third ditched it for poorly drawn, polygonal, chibi abominations that turn into full-size people only in combat. These large-eyed dwarves somehow have LESS ability to express emotion than the previous installments, in which expression was left up to a small picture of the character next to the dialogue window and consisted only of about four expressions (neutral, angry, sad).
Captcha: ppictut successive
as in
Make your art-styles consistent