I have one running now. Its a Nano Kitty.
They do not pause. They are fun, but if you are looking for growth like a tama... Its very basic.
The two games are Choose a side (In which it is very simmilar to an original tamagotchi game) The other game is Chase. (Which you go to catch a mouse in 20 sec.) Very simple games.
It will let you know when it is doing something of value (Or lack of......bathroom) With a ?! symbol. It shows up when it goes to the bathroom, needs cleaning, is thristy, needs food or discipline. Or when all the hearts are not filled in. (Like a tamagotchi levels of happiness/hunger)
When in has no hearts, after a while it can/will become sick and will need to go to the doctor. At that time, it will not eat, play or take any cleaning.
When it needs cleaning. Pawprints will show the screen. Eventually it becomes important to do so. To be fully clean at that point, it needs to be cleaned 3 times... Maybe less depending on how long it has been like that.
It will fall asleep at random times. Then it will ask you to turn off the lights. (The ?! will show) Then again when it wakes up fairly soon. Then will resume play.
I guess if you have other questions you can ask me. I think I covered basis though as nobody has responded to this for a few years now....