Mario And Luigi: Partners In Time Codes -

Dodge attacks:
During a battle press Attack for Mario or Luigi to dodge enemy attacks.

Double damage hammer in Piggyback mode:
Attack an enemy with a hammer. When it shakes, press the baby's button and the big Bro. will stand the baby up. Then, press the button again to do double damage.

Peach's Castle: Prince Peasley poster:
In Peach's Castle (Present), go into the item shop. Walk up to the counter, and behind the Toad that sells items is a poster of Prince Peasley from Mario And Luigi: Superstar Saga.

Yoob's Belly: Anger the dinosaur:
While in Yoob's belly, use the Baby Drill ability to tunnel underground. On the top screen, Yoob will be angry and have steam blowing out his nostrils.

Yoob's Belly: Easy beans:
While in Yoob's Belly, after the babies spring up from the first room, the second room will be filled with beans.