Not to be a buzzkill, but isn't that the emeralds from Minecraft? Are they open source or do you have permission to use them? Also, they seem a bit missplaced, as they have a higher resolution than the rest of the game
The emeralds are inspired on the minecraft ones, but they're actually an original pixel art by Aethon056, from DeviantArt, and I've got the permission to use them :)
 "ZS Dead Detective - Roving Eyes"){kind=icon}
 "ZS Dead Detective - A cat's chance in hell"){kind=icon}
 "Reaper of the Undead"){kind=icon}
The emeralds are inspired on the minecraft ones, but they're actually an original pixel art by Aethon056, from DeviantArt, and I've got the permission to use them :)