As the pilot of the severely damaged Zaku II tried desperately in vain to get his Mobile Suit upright again, the hidden Guncannon crashed through the jungle to finish what had only begun seconds before. With a final blast through the chest armor of the Zaku II, the Guncannon's pilot grinned, 'Game Over...'

More info at The Ghost of Zeon : http://www.ghostofzeon.com/complete/gcan/gcanzaku.html