Here is the full list of all 29 God of Rock achievements.
During overtime score 40 flawless notes in a row in an online match
Win over 100 online matches
Reach over 200 Combo Streak
Deal over 50 damage in less than 8 seconds as Johann in an online match
Recover 100HP in an online match as Hilde
Play over 50 quickplay matches
Score a total of 1000 perfect or flawless
Have your opponents fall for Rosetta's trap notes a total of 50 times
Play through every song
Have Champ's meter fully charged for at least 5 seconds
Have 20 active bubbles during Queen's Ultra
Leave your opponent dizzy for at least 8 seconds as Ziggy
During Ollie's Trick Combo reach at least a 5x combo streak
Execute a Reversal on your opponent's Reversal
Reach 80 Combo Streak
Win a match against a 'God of Rock' tier AI
Perform a total of 50 Reversals
Complete all tutorials
Create a custom beatmap
Play an online match with a custom beatmap
Win a match against any AI tier
Play 25 matches in Quickplay
Use the full extent of King's Light of Grace at least 3 times in a match
Win a match with every character
Use and alternate between Kosaku's Fire and Ice attacks 2 times in a row
Only use the charged version of Tophat's special moves during a match
Reach 40 Combo Streak
Execute a Reversal during a match
Win an online match