What is the difference between assassins creed 1 and 2

1. you can swim
2. the only weapon you have is the hidden blades. you have to disarm enemies for others
3. there are other ways to assassinate like from in a haystack or if a guard is over a ledge you can kill them while hanging.
4. there is a new player named Ezio instead of altair
5. there are bat like shaped flying vehicles you can use.
and 6. it takes place in Italy during the renniscance