The gap is indeed bigger, and there are even bigger gaps to come after that one. Be prepared.
1. play maps that are above your skill-level. Don't play stuff that you can get S-ranks on easily. Playing for A or B ranks is the way to go.
2. If you don't play with keyboard already, switch to keyboard + mouse, or keyboard + tablet. That way, you can click a lot more coordinated (with your keyboard).
3. You might have noticed weird circle patterns, where there are lots of circles either stacked on each other, or directly next to each other. (like this:
https://www.youtube.com/watch?v=ecyNfc4cA7Y ). you need to play the stacked patterns with both fingers, because one wont be fast enough. Definitely get used to that.
4. Practice, practice, practice
5. unrelated: This thread belongs in
13 (Gameplay and Rankings), not in General Discussion.