Utterly useless without connectivity to a watch device. I used both a mi band and let the game run on my mattress and the band actually noticed the times I woke up in the middle of the night and fell asleep again, while the phone just kept chugging on deep sleep. I can’t trust its numbers.

Also, I’m lucky to have an actual OLED screen, so I’m not concerned about the way the game does screen off. But most don’t and this game is way more wasteful too.