- When a character faints. When the adult faints, their younger self drags them to safety, and if one of the Babies, the other starts to cry and then carries the other for the rest of the duration of the battle! It brings tears to your eyes.
- None of the bosses which are obviously sapient show any hesitation in attacking Mario and Luigi while they are carrying their baby selves on their backs. Not to mention that killing their baby selves would affect other characters more than just emotionally. This becomes despicable and heart-wrenching for the player when the adults faint and cannot continue battling, prompting their baby selves to drag them away to safety and you are left...fighting the ruler of an entire race of aliens...as toddlers. To make it even worse, once one of the babies faints the one that's still standing will cry out the name of his fallen brother in grief, run over to him, and attempt to continue to survive enemy attacks while carrying his unconscious brother on his back, noticeably strained by the weight. To make matters worse, it makes it much harder to dodge enemy attacks, making it all the more likely for you to fail in doing so and letting the last brother awake get KOed.
- When Toadbert, Toadiko, and Kylie turn into Shroob Mushrooms.
- The whole section at Hollijolli Village, pictured above. The music is a very eerie rendition of Jingle Bells, and it's a town that got destroyed by Shroobs while they were celebrating Christmas. And they're harvesting the souls of the towns people for UFO fuel. On Christmas.
- The end of Mario and Luigi: Partners in Time. The Shroobs are all defeated, and the past! Mushroom Kingdom is now safe and restored. But Young Toadsworth, and the babies of Peach, Mario, and Luigi have to go back to their own time for good, never to see their future selves again. Baby Luigi goes up to his adult self and gets on his shoulders, ready to go on another adventure; but when he realizes he'll never see his future self again, he cries. Luigi gives Baby Luigi the last Yoshi Cookie he had been holding onto, which cheers the little guy up. He rewards Luigi by tossing him a hammer...which then promptly bonks Luigi on the head.
Tear Jerker / Mario & Luigi: Partners in Time