how can i change camera resolution throw the game to a certain value
take a look here:
this way don’t work throw the game
The resource i showed is indeed a launcher, you can see how i have done it and implement it in your .blend/game. All the things you need are there.
You can set the Window size with the following command.
Note: this does not effect the actual screen resolution relative to the application window.
Use a pixel post processing shader for a pixally look instead.