Defeat the Boss on Level 5-6 (Cleavage) in Normal mode on the Normal difficulty to unlock the Hard difficulty.Insane mode
Successfully complete Bonus Mode 2 to unlock the Insane difficulty.Nightmare mode
Successfully complete Challenge mode Stage 99 to unlock the Nightmare difficulty.Achievements
Accomplish the indicated achievement to get the corresponding number of Gamerscore points:
- Classic UFO Hunter (10 points): Eliminate all UFOs in Stage 0.
- High Score Of 10,000,000 (10 points): Acquire a high score of 10,000,000.
- 1,500 Chained (10 points): Achieve a chain of 1,500.
- 1,000 Nagoya Attacks (10 points): Perform 1,000 Nagoya Attacks in a single stage.
- Music Fan (10 points): Play Music Mode 10 times.
- Easy Difficulty Clear (10 points): Beat Normal Mode on Easy.
- Normal Difficulty Clear (15 points): Beat Normal Mode on Normal.
- Hard Difficulty Clear (20 points): Beat Normal Mode on Hard.
- Insane Difficulty Clear (20 points): Beat Normal Mode on Insane.
- Challenge Mode Clear (20 points): Beat all 99 stages in Challenge Mode.
- Continue-Free Clear (25 points): Beat Normal Mode without using any continues (on any difficulty level with any number of ships).
- Nightmare Difficulty Clear (40 points): Beat Normal Mode on Nightmare.