- Weapon upgrades
Successfully complete the indicated task to get the corresponding weapon upgrade. Each weapon has two upgrades that are treated as additional weapons. They can also be used with a new game on the same saved game file.

Grenades level 2	Successfully complete Missions 1, 2, and 3 on the Normal difficulty with an 'S' rank.
Grenades level 3	Successfully complete Missions 1 to 8 on the Hard difficulty with an 'S' rank.
Shotgun level 2	Acquireed from box in Mission 11.
Rocket Launcher level 2	Successfully complete Missions 9, 10, and 11 on the Normal difficulty with an 'S' rank.
Rocket Launcher level 3	Successfully complete Missions 1 to 12 on the Ultra difficulty with an 'S' rank.
Shotgun level 3	Successfully complete the game on Expert difficulty.
Whip level 2	Successfully complete Missions 5, 6, and 7 on the Normal difficulty with an 'S' rank.
SMG level 2	Acquireed from box in Mission 3.
Assault Rifle level 2	Acquireed from box in Mission 5.
SMG level 3	Successfully complete the game on Hard difficulty.
Assault Rifle level 3	Successfully complete the game on the Ultra difficulty.
Whip level 3	Successfully complete Missions from 1 to 8 on Expert difficulty with an 'S' rank.

- Fewer enemies
- Ultra mode
Successfully complete the game on the Expert difficulty to unlock the Ultra difficulty.

- Destroying multiple enemies
- Expert mode
Successfully complete the game on the Hard difficulty to unlock the Expert difficulty.