Here is the full list of all 11 Soundelta achievements.
Play all tutorials
Clear all maps in OST Pack 1 on any difficulty
Get an E rank score
Perfect Clear a map
Ultra Perfect Clear a map
Clear a map on Extreme Rate
Clear a map with only 1 Missed
Clear a map with 1 Almost and the rest all Perfect/UPerfect
Clear a map with 100 health and 50 over health on Normal Rate
Clear a map with 100 health and 100 over health on Extreme Rate
Earn 1500 or more SP from a single play