If you get yourself killed, wait for the Game Over screen to appear, hold A + B + Down and press Start. If done right, you'll go to a Continue screen where you'll get 2 free continues.
At the difficulty selection screen, hold Up + Left + Select and press A to start the game. If done right, you'll see all the game's cutscene images one after the other.
Speedup The Time
While playing, press Start to enter the status screen and hold A + B + Select. This will make the time counter go faster. To see the changes in the counter, just press Start to go back to the game and enter the status screen again.