Embrace ambiguity

Instead of fighting the ambiguity of movement, embrace it.

Ambiguity in movement-based games arises from the fact that
  • no two movements are the same, and
  • most sensor data is messy.
Trying to force precision may only frustrate the player, and make the limitations of the sensor obvious in a very un-fun way. So instead of trying to remove this ambiguity, work with it: players enjoy surfing uncertainty and trying to figure out optimal strategies in a somewhat messy system.
 Kinect Adventures  Pixel Motion
In Kinect Adventures, leaning to the side to control the raft is ambiguous. The sensor and the leaning is not precise; for example, does the twitching of your hip matter: would the sensor pick it up, and does it matter for controlling a raft anyhow? However, this feels okay during play, given the nature of rafting on water. The player expects the water to move the raft around unpredictably to a certain extent anyhow, and applies his/her own movement to add to this action, rather than aims to control it fully. Compare this to a car racing game, where players would expect to be able to precisely control the car, and probably get frustrated if their bodily actions do not result in exact outcomes.
Pixel Motion's movement sensor is a surveillance camera that picks up overall motion flow patterns instead of tracking individuals. This allows for a group interaction with a 'more the merrier' feel to it. Anyone in the camera’s field of view can join in ‘wiping’ pixels off the video feed by moving around within the play space.  The lack of system coupling with individuals means that people watching feel more free to jump in and interact, which helps everyone succeed. The game takes advantage of the sensor ambiguity to encourage group play.

Strategies for designers
  • Get to know the limits of your sensors, and use these limits as a design resource. 
  • Construct the player's actions in a way that gives room for sensor error without drawing attention to it.
  • Avoid game mechanics that require precise control.
DOs and DON'Ts
DO use the ambiguity of movement and sensor data to enhance the game.
DON'T use buttons during the early development phase (even if it seems easier), as you will miss the opportunities arising from dealing with ambiguity.