I found a midi file on the web and it doesnt work well

Here is the source of the file: http://www.youtube.com/watch?v=Y9MtssSYHLc&feature=watch_response
As you can see, it doesn't work well on Synthesia.
After I open it with musescore when it playes it doesn't play well and I simply can't find the reason.

Many thanks to the helper!