Mario & Luigi: Superstar Saga Cheats

150,000 points
Get a picture at the starting screen

Infinite Coins
They're are five steps.
1. Shrink Mario with Luigi's hammer.
2. Change to Luigi's High Jump Ability.
3. Perform his High Jump on Mini Mario.
4. While Luigi's in the air press Mario's jump button.
5. Everytime you use it you get another coin, but Luigi loses one HP (Just as if he was attacked by an enemy). Luigi's Health can't go below one.
-from Jangoman

Continue after game over
If you lose all your lives without finishing a single level, press the fire button a couple of times at the Game Over screen and you'll get a new set of lives and are allowed to pick up where you left off, losing your score but keeping your items. This will not work anymore if you've finished at least one level