Here is the full list of all 53 ShineG Has Nightmares achievements.
Get Devil Minions
Get Magister's Regalia
Get Doom Blast
Get Primal Blessing
Get Savior's Glory
Get Slightly glowing green vest
Get Inlaid with ruby skirt
Get Glowing yellow skirt
Get Glowing purple skirt
Get Inlaid with topaz skirt
Get Little Devil's Gift
Get Nightmare's Gate
Get Glowing headdress
Get Charm
Get Rebirth of blue crystal
Get Red Devil's Horn
Get Devil's whisper
Get Devil's Wings
Get Devil's Claw
Get Cunning crystal
Get Nightmare Horn
Get Nightmare Wings
Get Druid's Crystal
Get Nightmare Claw
Get Gorgeous Lapis Lazuli
Get Brilliant Lapis Lazuli
Get Gorgeous Agate
Get Brilliant Agate
Get Brilliant Sapphire Crystal
Get Brilliant Ruby
Get Gorgeous Aventurine feldspar
Get Brilliant Aventurine feldspar
Kill the 7th BOSS
Kill the 8th BOSS
Kill the 9th BOSS
Kill the final BOSS
Get Dark Star
Get Gorgeous Ruby
Get King's Tears
Get Gorgeous Sapphire Crystal
Kill the 4th BOSS
Get Eternal Staff
Kill the 6th BOSS
Get Inlaid with red crystal of tight clothing
Get Glowing green vest
Kill the 3rd BOSS
Kill the 2nd BOSS
Get Dreamwalker
Get Cat ears
Get Inlaid with red crystal vest
Get Wisdom Staff
Kill the 5th BOSS
Kill the first BOSS