Kingdom Hearts 358/2 Days Cheats - Nintendo DS
King Mickey in mission mode - Finish story mode.
Sora in mission mode - Finish story mode.
Donald and Goofy in Mission Mode - Beat Story Mode once in any difficulty.
Xion in mission Mode - Beat Story Mode once in any difficulty.
Goofy - Play story mode to day 277.
Riku - Play story mode to day 171.
Unlock Theater Mode
Beat the game once.
Dual-wielding Roxas Character (Mission Mode)
Buy Zero Gear from the Moogle Shop after completing the game, equip it with Roxas, and add three Ability Units. If you are playing Mission Mode, this will let you play as dual-wielding Roxas. (In Story Mode, Zero Gear will gain the three abilities from the ability units, but it will revert to its original form, and you will not be able to dual wield).
To unlock crowns do missions on mission mode or multiplayer mode and beat the mission to get crowns. Then go to the shop and choose freebies to redeem prizes:
Aeroga (magic) - 130 crowns.
Adamanite X 2 (material) - 180 crowns.
Aero X 3 (magic) - 25 crowns.
Aerora X 3 (magic) - 80 crowns.
Blizzara X 2 (magic) - 40 crowns.
Blizzard X 3 (magic) - 15 crowns.
Crimson Blood (ring) - 160 crowns.
Hi-Potion X 10 - 50 crowns.
Lift Gear+ (3) (weapon) - 10 crowns.
Limit recharge X 5 - 75 crowns.
LV Doubler (6) - 260 crowns.
LV Quadrupler (3) - 220 crowns.
Magic unit (L) - 190 crowns.
Master's Circle (ring) - 358 crowns.
Cura X 2 (magic) - 35 crowns.
Elixir X 10 - 70 crowns.
Ether X 10 - 8 crowns.
Guard Unit (L) - 240 crowns.
Hi-Ether X 10 - 55 crowns.
Mega-Ether X 10 - 100 crowns.
Mega-potion X 10 - 90 crowns.
Megalixir X 5 - 120 crowns.
Mystery Gear (3) (weapon) - 60 crowns.
Panacea X 10 - 30 crowns.
Potion X 10 - 5 crowns.
Power Unit (L) - 170 crowns.
Premium Orb (material) - 140 crowns.
Rune Ring (ring) - 200 crowns.
Sliding Dash LV+ (L) - 150 crowns.
Slot Releaser - 65 crowns.
Slot Releaser - 1 crown.
Slot Releaser - 45 crowns.
Slot Releaser - 20 crowns.
Slot Releaser - 280 crowns.
Slot Releaser - 85 crowns.
Ultimate Gear (6) (weapon) - 110 crowns.
Valor Gear+ (2) (weapon) - 2 crowns.