Well, it's hard to make both in video or in coding. I think video is easier, but will take some of the fun from actually being able to play the game. I think that if you want it badly you can make only a video. But the game would suit better. The storyline can be big but think about it like this: separate all story sequences and cutscenes from dawn of sorrow. You will see that there is no such thing as a biiiiiiiig story. Not saying for you to change it, but making it shorter and getting rid of some unecessary parts may make it fit on a game. You normally should aim for -> more gameplay than cutscenes. The real problem is finding a coder and a spriter. For a big project like yours I would say that having 2 coders and some other guys making sprites would be better, cause it's easier for things to come along nicely. I don't know, I guess I have to say good luck, man!