Originally players had the option of manually turning off the light when the pet fell asleep (it would turn on the light by itself when it awoke).
The pet can "die" due to poor care, old age, sickness, and in a few versions, predators.
The player can care for the pet as much or as little as they choose, and the outcome depends on the player's actions.
The first Tamagotchis could only be paused by going to set the clock, effectively stopping the passage of time in the game, but in later models a pause function was included.
Pets have a Hunger meter, Happy meter, Bracelet meter and Discipline meter to determine how healthy and well behaved the pet is.
There is also an age and weight check function for the current age and weight of the pet.
V5 had the three children look outside on the window when they wake up in the morning and before bed at night.