Get a 10x multiplier
Miss 8 times in a row.
Kill 1000 grunts with the musket.
Kill 500 dodgers with the shotgun.
Kill 7 enemies during a single cane time.
Kill 250 behemoths with the ray gun.
Kill 1000 tanks with the ray gun.
Reach level 20.
Collect 2500 orbs in a single game.
Get a score of 20000
Use a last stand
Kill 5000 grunts with the ray gun