Though not as crucial an issue as the limited interactivity, another issue that drew criticism was the quality of the video itself. While the video was often relatively smooth, it was not actually full-motion as it was not of 24 frames per second or higher. In addition to this, the hardware it was displayed on, particularly in the case of the Sega CD, had a limited color palette (of which a maximum of 64 colors were displayable simultaneously), resulting in notably inferior image quality due to the requirement of dithering. Game designer Chris Crawford disparages the concept of interactive movies, except those aimed at elementary-school-age children, in his book "Chris Crawford on Game Design". He writes that since the player must process what is known and explore the options, choosing a path at a branch-point is every bit as demanding as making a decision in a conventional game, but with much less reward since the result can only be one of a small number of branches.