In 'Who's Gem Is This?', you play as a sassy, down-on-their-luck gem appraiser called Finn, who stumbles upon a mysterious, powerful gemstone during a routine evaluation. As word spreads in the underground world of jewel collectors, you quickly become embroiled in a chaotic competition among eccentric jewel thieves, disgraced nobles, and quirky rival appraisers all determined to claim the gem for themselves. Navigate outrageous and often hilarious situations across various colorful locales, striking deals, solving puzzles, and employing your wit to outmaneuver the fierce competition while uncovering the hidden secrets of the gem's origin.