When the metaphor isn't trying to be subtle and instead leans into the obvious themes

Celeste - Madeline is figuratively climbing the mountain of depression by literally climbing a mountain.

Squid Games - The Squid Games are about capitalism exploiting the poor and vulnerable.

Nimona - Nimona being a shapeshifter/outsider is an allegory for trans and genderqueer people.

Assassination Classroom - This one's almost cheating because it's the core premise, but assassination is used interchangeably with self improvement and learning.