Special mode puzzles:

Beat all puzzles in hard mode.

Hard mode puzzles:

Beat all puzzles in normal mode.

Mania mode puzzles:

Beat all puzzles in special mode.

Sonic Adventures Chaos:

Beat each of the twenty-five challenge mode levels to transform the mice into Chaos.

Nights angels:

Beat each of the twenty-five mania mode levels to transform the mice into angels.

Taunt:

In a battle game, press or hold L or R.

Dreamkey web browser:

This will require a Dreamcast keyboard, and can be used as a replacement for the standard Planetweb browser. Go to the Homepage in the main menu. Once the Chu Chu Rocket title appears, press [Ctrl] + O on the keyboard. The URL bar will appear, which allows you to type in any Internet address.

Keyboard shortcuts:

URL bar: [Ctrl] + O
Reload page: [Ctrl] + R
Bookmarks: [Ctrl] + B
Mail: [Ctrl] + M
History: [Ctrl] + H

Save pictures from the web:

Save pictures from the web onto the VMU while using Chu Chu Rockets Dreamkey web browser. Place the cursor over the desired picture and press X + A on the controller.