Care

This icon will light up every time your Tamagotchi needs your care.
Not answering in time will result in a care mistake.
There are two kinds of mistake: physical and mental.
The amount of mistakes will dictate the character your Tamagotchi grows into.

Type of call	Expected response	Type of care
0 Hungry hearts	Give meal	Physical
0 Happy hearts	Give snack Play	Mental
Call for no reason	Time out	Physical
Bad mood	Praise	Mental
Sickness	Heal	Physical
Sleep	Turn off the lights	Mental

You get 15 minutes to answer the calls. Except the sleep one, that one gives you an hour.
The icon will turn off if you don't do it in time. You will have made a care mistake.
Your Tamagotchi may start begging or get mad after you miss a care call.

You can fix these mistakes by [getting a high score in the games].

Death

Your Tamagotchi will die if:

You let them stay with zero Hungry hearts for twelve hours.
You let them stay sick for twelve hours.
They get sick four times during the same stage.
They get several care mistakes during the senior stage.

If the requirements are fulfilled, your Tamagotchi will start dying… On the rerelease, the Grim Gotchi will come for your Tamagotchi, but, on the original versions, you'll just see blinking skull.