2nd Quest:

At the title screen, press SELECT and choose "Game B".

 

Change Title Screen Colors:

To change the colors on the title screen into one of eight palettes, shout into the microphone on Controller Two while holding B on it.

 

Timers:

Hold A, B and Start with the combination of Up to enable a Counter, Down to enable a Game Clock, Right to enable a Timer and Left to enable a stopwatch and power off and on your console. If done right, the game will boot up with a grey screen where you can change the time and press A to see it.