I saw a game the other day based on memes so everyone has a handful of cards with ‘sayings’ or random sentences on them a photo card is placed in the middle and everyone has to chose a sentence to go with the picture and the person with the funniest wins. Google meme game and it should come up. Something a bit dwifferent for that generation. Other games you can get are things like timeline game (or Star Wars timeline for sci-fi fans) Wikipedia board game, brain box games with different themes etc
There is a mile between a theme and an instruction on what to buy. You are telling them what to buy.
A theme would be Disney, or retro, or 80s, or animals etc. Fluffy headphones isn't a theme it's an instruction and requires no imagination from the participants. How do you "tailor" a mermaid to a person other than pick a size/colour?