Launch the game for the first time!
Get the Zapper.
Survive spring!
Survive summer!
Survive fall!
Repel the Martian threat for good!
Save all the cows on every Story level of spring.
Save all the cows on every Story level of summer.
Save all the cows on every Story level of fall.
Save all the cows on every Story level of winter.
Save all the cows on every level of the Story mode.
Save all the cows on every level of the Story mode in Veteran difficulty.
Save all the cows throughout all the Challenges.
Save all the cows throughout all the Challenges in Veteran difficulty.
Save all the cows throughout the whole 'Weird Science' Challenge category.
Save all the cows throughout the whole 'Hard Rock from the Red Planet' Challenge category.
Save all the cows throughout the whole 'Zombies of Mars' Challenge category.
Save all the cows throughout the whole 'Maid Raid' Challenge category.
Save all the cows throughout the whole 'Ninjas in the Snow' Challenge category.
Save all the cows throughout the whole 'Back to Basics' Challenge category.
Blast at least 8 Martians with one Bomb!
Defeat a Winter Story level without letting one Cog disappear.
Behold a Cow going through a quantum wormhole!
Successfully start a chain reaction using 4 or more Explosive Barrels!
Use the Zapper to finish a Martian.
Witness or cause the collapse of a quantum wormhole.
Someone's gotta fire it before the end.
Survive all five 'This is Halloween!' bonus levels!
Save all the cows on all the 'This is Halloween!' bonus levels.
Save all the cows on all the 'This is Halloween!' bonus levels in Veteran difficulty.
Survive all five 'Meet the Martians' bonus levels!
Save all the cows on all the 'Meet the Martians' bonus levels.
Save all the cows on all the 'Meet the Martians' bonus levels in Veteran difficulty.
