While the game is loading press and hold the fire button on the joystick until the title/option screen appears. At the bottom of the screen you should see CHEAT MODE #1 ACTIVATED. This gives you infinite time.
While the game is loading press and hold 'F1' until the title/option screen appears. Now click on 'INTRODUCTION' and then the 'CREDITS' for the following cheat instructions:
To clear area in every level do this: Start from the top line, if there's a field, press the same-column-area of the lower line. Do this until you reach the bottom, now go to the top line, doing the same with the upper area. Keep doing this up-to-down-to-up job to find yourself an easy way out.