There are currently three secret ending I know of.
1) "Another side, another story" - the KH original secret ending.
2) "Deep dive" - Final Mix hidden ending (my favorite)
3) KH2 secret ending, which, in my opinion is the least helpful :P
Your clip was number 2.
Sig and Avy made my me!!!Brawl FC is 3394-4531-4018