His final student cartoon , '' Billy 's Balloon '' , is about an inexplicable attack on small children by malevolent balloons . It was nominated for the Short Film Palme d'Or at the 1999 Cannes Film Festival , and won the Grand Jury Award at the 1999 Slamdance Film Festival . In total , it won thirty three awards
1999 Cannes Film Festival
1999 Cannes Film Festival
Don Hertzfeldt