even if the game uses little gpu, sometimes is nice to use "windowed mode", and be able to set a resolution, so its possible to watch a video while playing, or just the option to check something else.

Maybe also graphic settings could very important later, if the game later evolves to include more options to toy with, for example, adding additional light sources, or moving them, and ambient effects to enhance or make more unusual animations (while keeping the hand drawn and frame by frame animation style); what i mean is mixing 2d fbf animation with particle effects or similar things, maybe also a few photo-realistic effects.