- Stage 6
Acquire at least four keys from any three stages to unlock Stage 6.

- Hard mode
Successfully complete the game on the Normal difficulty to unlock the Hard difficulty.

- Stage 5
Acquire at least four keys from any stage to unlock Stage 5.

- Stage 7
Acquire at least four keys from stages 1 through 6 to unlock Stage 7.

- Trophies
Successfully complete one of the following tasks to get a trophy:

Bronze Trophies
Piece of rock	Finish the third stage ('Ethia Ruins') at any difficulty level.
Action Fan	Clear challenge 'Action Fan'.
Survivor	Clear challenge 'Survivor'.
Chain Expert	Clear challenge 'Chain Expert'.
Lucky Number 7	Acquire an accumulated total of 77777 chain rings.
System liberated	Finish the fifth stage ('Turady Deep Sea') at any difficulty level.
Acquireor	Clear challenge 'Acquireor'.
Ready for the junkyard	Finish the first stage ('Zeus Sector') at any difficulty level.
Rating Expert	Clear challenge 'Rating Expert'.
Profiler	Clear challenge 'Profiler'.
Silver Trophies
Key Explorer	Acquire all 35 secret keys.
Gold Trophies
Challenge Master	Unlock and successfully pass 12 or more challenges.

Bronze Trophies
Not that difficult after all	Finish the seventh stage ('Van Krist Labs') on any difficulty level.
Silver Trophies
Can't hide from me	Shoot down a rare enemy.

Bronze Trophies
Hellfire	Clear challenge 'Hellfire'.
Stage Keys	Clear challenge 'Stage Keys'.
Kill Acquireor	Clear Challenge 'Kill Acquireor 1'.
Rank Master	Clear challenge 'Rank Master'.
Speed Gunner	Clear challenge 'Speed Gunner'.
Speed Acquireor	Clear challenge 'Speed Acquireor'.
Realize Acquireor	Clear challenge 'Realize Acquireor 1'.
The Last Chapter	Finish the tenth stage ('Inner Core') at any difficulty level.
Silver Trophies
Key Master	Acquire all 15 secret keys in stage eight through ten.
King of Unlockables	Unlock at least seven specials.

- Very Hard mode
Successfully complete the game on the Hard difficulty to unlock the Very Hard difficulty.

- Third ship
Successfully complete the 'Assassin' challenge to unlock the third ship.