To unlock unlimited credits, use 50 continues.

Unlock the following bonuses in the Japanese version of the game by performing the corresponding tasks:

BONUS - HOW TO UNLOCK
Arcade mode stage select - Successfully complete 13 Plane Arcade mode.
Extra stage select - Successfully complete 13 Plane Extra mode.
Rate Viewer - Successfully complete 13 Plane Arcade mode or 13 Plane Extra mode.
R-Gear Rollout - Successfully complete Extra mode.
R-Gray 0 - Successfully complete Arcade mode.

ACHIEVEMENT - HOW TO UNLOCK
Unlock Arcade Stage Select Mode (10 points) - Complete single player 13 Plane Arcade Mode!
Unlock Extra Stage Select Mode (10 points) - Complete single player 13 Plane Extra Mode!
Unlock 13 Plane Mode (10 points) - Complete single player Arcade Mode and Extra Mode!
R-Gray0 Rollout (10 points) - Complete single player Arcade Mode!
R-Gear Rollout (10 points) - Complete single player Extra Mode!
Unlock Rate Viewer (10 points) - Complete single player 13 Plane Arcade Mode or Extra Mode!
Unlock Unlimited Credits (10 points) - Use 50 total credits in single player.
Overall Lockon Average 80% (20 points) - In single player, get an average lock-on percentage of 80% on all stages!
Overall Shootingdown Average 80% (20 points) - In single player, get an average kill ratio of 80% on all stages!
Lockon Down 10000 Unit (20 points) - In single player, accumulate a total of 10,000 lock-on kills!
Shootingdown 15000 Unit (20 points) - In single player, accumulate a total of 15,000 kills!
No Continue Clear (50 points) - Complete a single player game (excluding 13 Plane Mode) with no continues!

Unlock the following bonuses in the North American version of the game by performing the corresponding tasks:

BONUS - HOW TO UNLOCK
R-Gear Rollout - Successfully complete Extra mode.
R-Gray 0 - Successfully complete Arcade mode.
13 Plane mode - Successfully complete Arcade mode and Extra mode.