- Mario (as well as the Babies) sticking up for a crying Luigi when the Star Gate refuses him entry (at first) merits for a heartwarming moment between the brothers. Baby Mario even starts whacking the gate with his hammer!
- Luigi giving Baby Luigi (as well as Baby Mario while inside Yoob's Stomach) Yoshi cookies.Baby Luigi: Thank you very much!
- The ending, when Baby Luigi wanted to stay with his older self. Baby Mario in contrast is immediately willing to leave, though he does offer Mario his hammer regardless. Baby Luigi eagerly gives Luigi his own hammer as well...only to accidentally clonk Luigi with it.
- When Baby Luigi is stuck on a metal rafter after the explosion, Baby Mario climbs up an empty chain to reunite with him. When they're reunited they happily call out each other's names, showing their close brotherly bond already existed when they were babies.
Heartwarming / Mario & Luigi: Partners in Time