The main villain attempts to kill his younger sister by crushing her with a boulder. He does not show any empathy upon doing so. She is physically okay afterwards.
There are various origami insects, both based off of the stylized design of Mario enemies, and based off of real life insects. Both are presented cartoonishly. A section of the game involves defeating small versions of a regular type of enemy in a restaurant setting, and NPCs react to these small enemies as if they were insects.
The main villain folds up characters into origami, which some characters say is horribly painful and in the beginning characters are kept captive in a dungeon.
Pokeys get reduced down to their head only and can be jumped on. The basic method of defeating enemies is to jump on them or to smash them with a hammer. In one scene a character is crushed by a large boulder. She is completely okay afterwards, but it does fall on her entire body (she is small.)
In two sections, a group of enemies attack with what is functionally flaming oil. These enemies can accidentally catch themselves or other enemies on fire, at which point they run around comically and turn into a pile of ash.
A party member is trapped under a large boulder on screen at one point, and the remaining members of the party leave the area in order to find an item that will save the party member. The party member is saved.
One character commits sacrificial suicide at one point, and is implied to be in his teens. Another child character is crushed by a boulder at one point, however she is alright afterwards.
In addition to the normal cartoonish ghost-like Boos regularly found in Mario games, a spirit of a deceased character briefly shows up to offer advice.
A few characters are trapped "in-between dimensions" (actually within a wall), and are rescued. A game over scene involves Mario being trapped in a large genie lamp.
It is possible to run over enemies while driving the Boot Car, causing them to explode in a shower of confetti and coins. Friendly characters jump out of the way, unharmed and unbothered.
At points throughout the game, the player can drive a boot-shaped car and a boat. If the player runs into an enemy on the overworld while boosting in either of these, the enemy will be instantly defeated and explode into confetti.
Defeated enemies explode into rainbow colored confetti. No actual blood or gore is seen. There is "paper gore" of sorts in a few sections, where the characters (who are made of paper) are cut or hole punched. These are later reversed.