Complete the first level.
Complete the first level after destroying all enemies in one session.
Complete the second level.
Complete the second level after destroying all enemies in one session.
Complete the third level.
Complete the third level after destroying all enemies in one session.
Complete the fourth level.
Complete the fourth level after destroying all enemies in one session.
Complete the fifth level.
Complete the fifth level after destroying all enemies in one session.
Complete the sixth level.
Complete the sixth level after destroying all enemies in one session.
Complete the seventh level.
Complete the seventh level after destroying all enemies in one session.
Complete the eighth level.
Complete the eighth level after destroying all enemies in one session.