Well the test game when i made it, 800x600 and made it fullscreen(1280x1024), it still looked "okay".
Modern games tackle this problem by either choosing the native resolution by default, or letting the user choose what resolution they want to use. It really is annoying to have to use a lower resolution that doesn't match the native res of your monitor, because then you get blurring. You can scale your sprites to match the resolution, or you can have different sprites created to match the different resolution, which is more work but creates better results. Either way, you really need to take into account modern hardware for this stuff.
I done understand how to do this :
Modern games tackle this problem by either choosing the native resolution by default, or letting the user choose what resolution they want to use
1: Choosing a native resolution? ( Like setting a 1280x1024 ? )
2: Giving a player to chose what screen resolution to use? ( A tips on how to do this would be appreciated )
I mixed people thoughts, i thought allowing application fullscreen. But when i think about it, almost each game has "Select screen size" and then you pick which one you want, but what does happen actually?