The fact that they "controlled" for genetics using polygenic scores already is a strong sign of low quality research. Polygenic scores are powerful, but they contain very large amounts of noise compared to the true genetic effects. Controlling for genetics using them is like controlling for income by asking whether the respondents own a Porsche. Also, be aware that Scientific Reports is, if not quite a predatory jour…
Pattern recognition+spacial rotation+quick answer to stimuli+repetitive tasks or short term memories, several IQ components are testing these. Kids might have higher IQ because of video games, but poorer to everything else that matters.
Sounds like we're training kids--through video games--to be fantastic CAD engineers and plumbers.