Two mobile games that look comparable can consume power at very different rates. The difference is usually not graphical complexity but how continuously the hardware is being asked to work.
Sustained load costs more than peak load
A phone can run its processors hard briefly without difficulty, because the chassis absorbs the heat. Sustained load is a different problem, since heat accumulates.
Once temperature rises the device reduces clock speeds to protect itself, which lowers performance while power draw remains elevated. Efficiency falls at exactly the wrong moment.
A game that runs its systems continuously therefore costs disproportionately more than one that idles between actions, even where the peak demands are similar.
Frame rate targets set the baseline
Rendering at a higher frame rate multiplies the work done per second across the whole pipeline, and the cost applies whether or not the extra frames are useful.
Menu screens and turn-based sections rendered at full rate are the most common avoidable drain, since nothing on screen requires it.
Games that cap frame rates outside active play, or that render only when something changes, extend battery life substantially without any visible difference.
The display is often the largest single consumer
A phone screen at high brightness can draw more power than the processor. On panels where each pixel emits its own light, bright scenes cost more than dark ones.
A game with a predominantly white interface therefore consumes more than a visually similar game with a dark one, purely through the display.
This is why dark presentation in mobile games is not only an aesthetic choice. On some hardware it is a measurable efficiency decision.
Network and location activity add hidden cost
Radios are expensive to operate, and a connection that is opened and closed repeatedly costs more than one used steadily, because the radio cannot enter a low-power state.
Games that poll a server frequently for small updates, or that load advertising continuously, keep the radio active far more than their gameplay requires.
Location services and background refresh compound this, which is why battery reports sometimes attribute large consumption to a game that was barely played.
Settings shift the trade rather than removing it
Lowering resolution, capping frame rate and reducing effects all reduce draw, and most mobile games expose at least some of these controls.
The reductions interact with thermal behaviour, so a modest cap can produce a larger gain than expected by keeping the device below the point where it throttles.
The remaining consumption is structural. A game designed around continuous action on a bright screen has a floor that no setting brings it beneath.