When you cant uninstall an application(most of the time Java games) using the Manager function of the phone, then do this;
1. Install FExplorer.
2. Launch it and goto the path/folder of the Application. I'm assuming you have install it to the MMC so the path would be something like,
E:\system\apps
and you will see lots of folders in there that is onlylabelled by numbers(for Java games/apps) or the name of the application. Go though them one by one. Open the text file in that folder to exactly know the name of the application in that particular folder if you dont see any icons or familiar name.
3. Then if its the correct folder, "move-out" of the folder, click on Options>File>Delete.
4. Then goto the Manager to uninstall it if its still listed.
5. Reboot.