No sounds?
If you use iPod touch (not iPhone), make sure that sound effects are from headphones (in Settings > General > Sound Effects, change the settings to Headphone or Both).
Because Shaka! Lite plays drum sounds or other sound effects to shaking iPhone / iPod touch, I think that iPhone is better than iPod touch to play Shaka! (iPhone has speakers).
If you set iPhone in silent mode, turn it to sound mode.