"Anything"... hum that was an easy one.
This engine is pretty cool and functionnal. Moreover, it can be easily included in a Zelda made on MMF.
The only thing you may change is the moment when the boomerang come back to Link and vanish. In fact, it seems like if the boomerang vanish without any reason just near to Link. (let the boomerang come a bit more next to Link before make it disapear)
//Bad english sorry ...