Reach the 21th wave.
Reach the 17th wave.
Reach the 15th wave.
Reach the 13th wave.
Reach the 11th wave.
Reach the 10th wave.
Reach the 8th wave.
Reach the 7th wave.
Reach the 5th wave.
Reach the 4th wave.
Reach the 20th wave.
Reach the 19th wave.
Reach the 18th wave.
Reach the 16th wave.
Reach the 14th wave.
Endure 3 waves with 1 piece of baumkuchen remaining.
Reach the 12th wave.
Reach the 9th wave.
Shoot 200 bullets while the rate of fire is increased.
Shoot 100 bullets while the rate of fire is increased.
Reach the 6th wave.
Increase the crew to five.
Kill 50 of them with the increased damage of the bullets.
Kill two or more enemies at once with a single laser shot.
Lose your first game.
Reach the 3rd wave.
Gain a skill for the first time.
Increase the crew to two.
Clear your first wave.
Defeat an enemy for the first time.