Boost stage with metamorphic graphical element

In an electronic gaming device, a boost stage uses a metamorphic graphical element. The boost stage starts when predetermined condition such as a "near-miss" condition occurs and provides an additional opportunity to satisfy a trigger condition for a supplemental feature. The metamorphic graphical element indicates how many times the predetermined condition has occurred since the supplemental feature was last triggered. When the boost stage starts, the state of the metamorphic graphical element can advance to a higher state value, visually indicating the additional opportunity to satisfy the trigger condition for the supplemental feature. For the boost stage, if the previous result (associated with the predetermined condition) is enhanced enough to satisfy the trigger condition, the supplemental feature is triggered and the metamorphic graphical element is reset. Otherwise, the boost stage finishes but the advanced state value of the metamorphic graphical element is maintained.