Here some thing thats helps u
Tap at player cube, and add rule
WHEN [this is not in camera viewpoint]
|DO [Destroy this actor]
|[Create a text block with message. |(defeat){When tapped=Do nothing}
|[Create a text block with message (restart)
||{When tapped=do a response}
||[Restart this card]
This will kill player if he fly away from card borders, u can add something other, but this is a classic.