You may be able to use your USB Joypad. Install the joyenabler script [joyenabler_1.3_arm.ipk] and plug in your joypad. If you are lucky, it will work and you can use jstest to check whether it works correctly. Now you just need to find some games that support joypad controls. You may need an additional joypad driver for your particular joypad if it does not work.