Now just so you know, the game will crash if your computer can't use the custom resolution in fullscreen! - Also meaning you can't make a windowed resolution of say '700x400' if your display doesn't have the option for fullscreen! It can also enable the unused 'Windowed mode' in params.txt if you specify it. So this tool (written in Blitzmax which also includes the sources), allows you to input any resolution that your computer can use in 3D mode. I have made a custom tool for Magic Ball 2 to change the resolutions, as the game has predefined resolutions for some reason.