Battery and heat
Frame-rate caps are the single most effective setting. Dropping from 60 to 30 frames per second in a city builder is barely noticeable and can nearly halve power draw.
Playing while charging generates heat, and heat causes throttling. If you can, charge before playing rather than during.
Data use
Download large asset updates over Wi-Fi and check whether the game offers a high-quality asset pack you can decline. Persistent-world strategy games use very little data in normal play; action MMOs use considerably more.