Mark Zero is a browser flight sandbox built around one question: what would a powered armor suit actually feel like to fly? You start as a person on foot. You step onto a platform, the suit assembles itself around you plate by plate, and then the sky is yours up to the edge of the stratosphere.

The flight model is six degrees of freedom with thrust in body-local axes, which sounds technical but produces something simple and satisfying: spin around mid-flight while still travelling forward, hit the throttle, and your own engines slam you to a stop. That hard brake is not a scripted move, it falls out of the physics. Hands and leg thrusters animate automatically to match the thrust vector, so it looks like you are steering with your palms while you are really flying a full 6DOF craft.

The suit is a separate entity from the player, not a costume. Leave it standing in a field and walk away. Call it and it flies to you across the map and closes around you mid-stride. Eject at three hundred metres per second and you fall as a person while the armor chases you down and catches you before the ground does.