This will work about 95% of the time on S60 3rd edition phone models. This will not work on phones with a landscape screen (E series). This will work with any MIDlet by the way, not just games.
To Do it, follow this steps
1. Using an archiver such as WinRAR, open the jar file.
2. Once you have opened the jar, you will see a folder called 'META-INF'. Open this folder.
3. In the META-INF folder there will be one file called 'MANIFEST.MF'. Drag this file onto your desktop and open it in notepad.
4.
Now you must know 2 things to edit the file. First, you must know the
original resolution of the game. Ususally this information can be found
on the author's website. Second, you must know the resolution of your
screen. Then type the following two lines at the end of the text in the
MANIFEST.MF file:
