Sorry for the late reply and thank you for your feedback.
Wokamon is our first fitness game and I agree with you the game system is not very complex. We are actively looking for breakpoints to add new game systems in Wokamon, however it's not that easy to make drastic changes to a game which is already online and with thousands of active players. We are still of course making small changes bit by bit to improve the overall game experience.
If you are looking for a fitness game with more game play, why not give Pocket Plants a go? Pocket Plants also collects your steps and turns them into energy. You use the energy to grow and collect magical plants.