Before using the following codes you'll need to activate Cheat Mode. To do so, press 1 + 4 +7 + A at the main menu.
Enable Rotary Controller
To use a rotary controller, go to the Game Option menu and press Pause on both controllers.
Start any Tempest Plus game and hold Option until you get to the rainbow levels. The web will be invisible during the rainbow levels only.
To skip to the next level, press Option while playing.
While selecting a web, you can change its rotation by press Up or Down to change the level and pressing Left or Right to change the rotation.
Warp Bonus Round
To enable the Warp Bonus Round, press 6 while playing.