Beat Boss 1 with 50 seconds or more left on the clock
Beat stage 1
Beat stage 2
Beat stage 3
Beat stage 4
Defeat the stage 1 boss
Defeat the stage 2 boss
Defeat the stage 3 boss
Defeat the stage 4 boss
Make 30 kills on stage 1
Make 25 kills on stage 2
Make 26 kills on stage 3
Make 30 kills on stage 4
Finish the game with no deaths
Play the hidden ? stage (method is in the achievement comments)
Find the secret battle with your captor (method is in the achievement comments)
See the test stage (method is in the achievement comments)
See the special thank you screen (method is in the achievement comments)