Here is the full list of all 33 Re:Kuroi Demo achievements.
All Achievement Clear
Challenge Master
EnemyInfo Master
All MagicExp Max
All Actor LvMax
All Magic Master
Fire Magic Master
Quiz Master
Black Magic Master
Ice Magic Master
Thunder Magic Master
White Magic Master
All Stage Clear
Stage20 Clear
Stage19 Clear
Stage18 Clear
Stage17 Clear
Stage16 Clear
Stage15 Clear
Stage14 Clear
Stage13 Clear
Stage12 Clear
Stage11 Clear
Stage10 Clear
Stage9 Clear
Stage8 Clear
Stage7 Clear
Stage6 Clear
Stage5 Clear
Stage4 Clear
Stage3 Clear
Stage2 Clear
Stage1 Clear