Get blown up by a barrel
Die for the very first time.
Take down your very first zombie.
Complete the first level.
Complete the second level.
Complete the third level.
Complete the fourth level
Complete the fifth level.
Complete the sixth level
Complete the seventh level.
Complete the eighth level.
Complete the ninth level.
Complete the tenth level.
Kill 100 zombies
Kill 500 Zombies
Kill 1,000 Zombies
Kill 2,500 Zombies
Kill 5,000 Zombies
Kill 10,000 Zombies
Kill a zombie with an explosive barrel
Kill a zombie with the flamethrower.
988
40354
1501147
292842
26010
5513
7671
1160