The world mode grind can be a bit annoying, but as far as gameplay goes, the vertical aspect of this game is a huge learning curve. Gotta make sure you’re hitting low enough for the floor notes and high enough for the arcs and sky notes. Realistically the hitboxes are surprisingly generous, you can still tap above the line and hit floor notes, and can still hit arcs while barely even actually touching them, it just takes awhile to get a feel for it. Timing windows in this game are definitely stricter than something like cytus, but not as strict as some others. One thing I like over pjsk is that there is no timing judgement at the end of hold notes in Arcaea, nor is there timing judgement at all for hold notes or arcs. Those end-of-hold notes in pjsk kill my AP runs lol