Level chart provided by Yakamino- some entries may be incorrect; as I did not test all 60. But this should be a good guideline.
"Enemy Kills & Bullets Grazed" is incorrect. Top value is normal kill, bottom is chain kill.
Jiiya unlocks at 10 medals collected. Baf unlocks at 10 silvers (or better).
To force unlock the characters, throw system.sav into a hex editor and change the data from 00000020 to 00000070 to look like so : https://ibb.co/X8fYm8h
00:00 Intro
01:00 The Roots
03:30 Combination of Genres
05:40 Sispri Gauntlet
12:50 Scoring
14:37 The Sisters
20:28 Rushing Into
23:05 Cracks in the Glass
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