You can resolve these issues by:
Reducing the graphics settings puts less strain on your device, allowing it to run at a smoother frame rate and saving power and energy for focusing on smoother gameplay.
While features such as shadows, anti-aliasing etc. make a big impact visually, they also make a big impact on performance. If you find your device is struggling to play smoothly, consider turning off unnecessary features.
Having other apps running in the background while playing Starvara uses up resources that could be better dedicated fully to your gaming experience. By closing other apps you free up resources that can be used by Starvara to run more effectively.