A significant part of the game's progression involves unlocking new characters and alternate costumes. These unlocks are tied to achieving specific ranks on missions.
- New Characters: Typically unlocked by achieving an A-Rank or higher on specific missions. For example, getting an A-Rank on Mission 1-1 might unlock a new character. Consult the in-game unlock requirements for precise details.
- Alternate Costumes: These are usually unlocked by achieving S-Ranks or SS-Ranks on missions with a specific character, or by completing all missions with a character. Costumes are purely cosmetic but add replay value.
The game encourages you to play through all missions with every available character to unlock everything. This provides a fresh challenge as each character has a unique loadout and special attack, requiring different strategies.