Out of the three tiers, the third and last one is the toughest. It introduces fresh, more complex challenges like gravity flips and faster leaps in addition to all the geometry dash subzero principles you have learnt from the past levels. Here the difficulty curve peaks, hence finishing this level is quite a success.
This level also tests your capacity to keep in time with the music since the rhythm and timing are more strong here and will help you negotiate the anarchy.