This is just tinkering at the edges. Who is to decide which company can swallow another, and why limit ourselves just to the gaming industry? What about energy companies, chemical giants, pharmaceuticals, food conglomerates, social media platforms, and countless others?
We need a systemic solution: progressive corporation tax. The more market a company controls, the larger its tax. Anything above 10% of market share should be taxed at 99%. Then you don't need antitrust laws.
Can you imagine the boost to competitiveness and quality of software if Microsoft, Apple, Google, Amazon, Facebook, Intel, AMD, Ebay, PayPal were forced to split into numerous competing companies? We would have Windows 20 next year, and it would not be snooping on you any more.