Metal Gear Acid [PSP]

In the main menu, select Password and enter the following passwords:

Password - Effect
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Elyts - Gives Card No.202 - Saitou Yuu
Karen - Gives Card No.182 - Karen Houjou
Jehuty vGives Card No.184 - Jehuty
Mika - Gives Card No.178 - Mika Slayton
Maeb - Gives Card No.203 - Shibuya Eri
Nomel - Gives Card No.201 - Yoshida Asaki
Sabrage - Gives Card No.200 - Kosaka Yuka
Viper - Gives Card No.173 - Viper
Xmeight - Gives Card No.199 - XM8

Bikini model clip:
Enter SABRAGE, NOMEL, ELYTS or MAEB as a password to see clips featuring Japanese bikini models. Note: These will cause Snake to get a nosebleed, but has no effect on Teliko.

Link battle option:
Successfully complete Stage 06 to unlock the "Link Battle" selection at the "Options" menu under the "Intermission" screen.