Plant Nanny is an adorable app that is designed to remind people to drink more water. It isn’t a video game, but it does include gamification (in a similar way to the Epic Win app).
The goal is to grow a variety of cute plants from a seed to Level 4. After a plant hits Level 4, it goes into your permanent garden and grows more seeds for you. Every time you drink water you are supposed to go into the app and give the plant you are currently growing a virtual drink.