I felt the need to deliver a critique- basically, it's a good idea, but some more characterization and fleshing-out of scenes would definitely have been welcome. Also, some of the casting choices were... rather meh, to say the least. For example, when I saw the description of Ryo-Ohki for
Game & Watch I initially thought of "Hello Kitty" which would have been hilarious. Instead of Speed Racer for
Falcon you really should have gone with
Kamina, who would have fit the character perfectly. Not to mention that
Lelouch would have fit rather well as
because, well, [[spoiler:Huey Freeman?? Really? NoJustNo. I understand your idea, but that one was just out of left field and pretty much threw the rest of the story out of whack. Also, I would've gone with Kuriboh instead of Dark Magician for Pikachu, and I'm a little thrown by how most of the Yu-Gi-Oh! characters are more like their abridged counterparts. One final bit of casting advice-
Lagann's Anti-Spiral for Tabuu, mostly because he looks and fits the part far more (and because I have no idea who the hell the guy you chose is). That said, your casting of Sailor Moon, Kenshin, Luffy, Inuyasha, Yusuke, Spike, Shinji, and Goku all fit remarkably well into the pre-existing plot, although I feel kid Goku would have been better than his adult counterpart because the power discrepancies are a bit unbelievable. Also, I have to give you an A+ for
as Master Hand, which is a brilliant and hilarious idea. Basically, I feel that you have an OK start, but I would suggest rewriting it later on, in order to expand the plot and characterization more, and perhaps to look into more anime to find more fitting cast counterparts.