Woah
I didn't even think it would have been possible to re-create SSBM In flash- but it seems so!
You captured the menu perfectly, which is a big plus.
The In-Game Mode was probably the best you're going to get for the flash, despite several control bugs I have encountered.
One thing you might want to fix is the character's registration points. Maybe it was just Link, but when he turned he 'jumped'. This can easily be fixed by making his registration point at the very centre, not towards the left / right.
The only other problem was that there was only one attack key >:(
Apart from that, great work! That must have taken ages to code, and I assume wasn't the easiest of all tasks
^_^