It's basically a perfect introduction to 2D Sonic for the mainstream of today. I would have loved to see more original zones than just the four. Titanic Monarch is one of my favorite final stages in the Sonic series, it has a truly authentic sense of challenge to the platforming. It's easy to clear while Super, but if you somehow didn't get the emeralds by this point (because the Special Rings are spammed), just take it slow and practice :)