EveryGameSearch, despite any features that it may boast of having, is nothing more than another browser-hijacker application. Its primary purpose is to take over browser-settings to promote and drive artificial traffic towards a fake search engine - everygamesearch.com, in this case. It should be noted that such browser-hijacker applications are categorized as Potentially Unwanted Programs (PUPs) due to being distributed through deceptive or misleading marketing tactics mainly, such as 'bundling.'
The specific manner in which EveryGameSearch enters the user's device doesn't affect its activity - immediately after being installed, the application will change the settings for the browser's homepage, new page tab, etc. and the default search engine. Every time the affected browser is opened from there on, it will redirect the user to the everygamesearch.com. The same also is true for every search query. On its own, this search engine cannot provide any search results at all, as it simply lacks the functionality. That is why it takes the user's search query and redirects it once more, but this time through a legitimate search engine - search.yahoo.com.
Users who notice any signs that point towards EveryGameSearch being present on their devices should take the necessary steps to remove the application. There are multiple reasons to do so - browser-hijackers are known to inject sponsored advertisements that could lead users to dubious third-party sites into the list of displayed search results while tracking and collecting various browser and system data simultaneously.