well..it was bad.. but good for your first i guess
it wasnt real
when youre making a movie you gotta think "what would it really be like?"
and then animate based on that
like. the cannonballs just bounced off. and when a cannonball bumped the other, it rolled.. heavy cannonballs arent supposed to roll because they get bumped :P
and the castle falling wasnt too realistic.
the castle fell, and just slid over the tops of the cannonballs
when it should have crumbled o_O
but yeah since you were only experimenting with tweens
good job with those