it would be awesome to play as riku in both KH1 and KH2 but it would spoil wat was about to happen and if u played rikus story after u have completed it there is no point as you know what is about to happen. if they did have a seperate part of the game where u play as riku it would have to cut into soras play time and then keep swapping as they meet up in the end. as for COM they do not meet so they had a chance to make a sepeate story as they follow different paths...sora still wants to find kairi and riku as riku wants to save mickey. (i hope u understandwat i mean lol)