Thats the guys page, but the video is not there anymore, you can probably find it through google, one filename is Ikaruga_DP_NORMAL_chapter3_8649k_WH.wmv, there are a few of them.
I think what you mean is one guy playing both first and second player right? I don't know where those videos are now but here you can download videos of 2 guys playing together in perfect unison to get S++, personally I think this is even more difficult than just one guy playing both ships. http://www.sirkain.net/~kiken/ikarugareplay2.html