I didn't watch the video
but I was a big katamari fan back in the day
I think the katamari has phyics, and I think it's kindof similar to the oval thing
or else it would never roll with a big pencil sticking out
check out the platform school tutorial...I'm not sure which one, but it uses an invisible sprite to control collisions
it's quite simple though, you can try it for yourself
I don't have much time at the moment to make a cap, but try this
right click the ball we have now
then right click on blank space
right click - then paste clone
this makes it paste a whole new object, not just a copy of that object
now the new sprite
go into behaviors, and delete the physics behavior
edit the sprite of the original object
just color it green or something
make that sprite invisible
it's at the bottom of the properties panel
start invisible
now make a new event
system-always
in this event create an action
double click the new sprite (that looks like the one we've been using, but has no physics now, remember)
doubleclick on the action set position to object
and then choose the green physics object as the object
create another new action under that one
again with our new sprite(not the green physics sprite)
the new action will be set angle
now play it again
it should look and play exactly the same as it did before
if it does that means, you did the invisible sprite thing