Mario & Luigi: Partners in Time
Nintendo DS Cameos
DS Remote Control
During the game, the Shroobs and Professor E. Gadd use remote controls shaped like the Nintendo DS.
Submitted by GameHiker
Prince Peasley Poster
In the castle's shop, you can see a poster of Prince Peasley, the dashing prince of the Beanbean Kingdom from Mario & Luigi: Superstar Saga.
Submitted by Flip
Poltergush 9000
At one point, Professor E. Gadd puts out a fire with a water pump called the Poltergush 9000, a combination of FLUDD from Super Mario Sunshine and the Poltergust 3000 from Luigi's Mansion.
Submitted by Flip
Handfake
The Handfake enemy is a hand made out of ooze that holds up a sign to determine how it will attack. The signs feature official artwork for Super Mario Bros., Super Mario Bros. 3 and Super Mario World.
Submitted by Flip
Not in Another Castle
At one point in the past, Baby Peach gets lost in the Mushroom Castle, and a young Toadsworth says:
"You will save her, won't you? I assure you, she's NOT in another castle or anything."
This is a reference to the phrase "Thank you Mario! But our Princess is in another castle!" from Super Mario Bros.
Submitted by TrustTheFungus