Could I Get One Secret Code?

Sure...

In the game 'Mr. Mosquito' for the PS2, when you are on the opening selection page (before actually starting or continuing a game), rotate the right analog stick on your controller counter-clockwise 30 times. The game will automatically fade to black, and launch a secret game that comes as part of the disk, that is what looks like two Japanese middle managers (balding, a bit of a paunch) on bicycles on top of a round stone pillar trying to knock each other off the top. It's a two player game, so there's no point in doing it alone, but with two people, it's really funny, and a lot of fun.

No joke here. I thought it was bogus until I tried it on my copy, and just about fell off my chair laughing when the game came up. There's your one free secret code... Hope you enjoy it! (^_^)