Valentines Chocolates( candy matching slot)you may Even be able to Find Some Sponsors this way) say matching 5 kit kats get you 3000 Coins) or Matching 5 recces peanut butter cups gets out 50,000 or match Five Milky Ways is Jackpot)

Another idea is Matching Crystals, or Crystal Skulls(there are Beliefs that these 13 Crystal Skulls were Made by Aliens( 1 of them is still missing to this day)

matching the 8 Wonders) There are 8 Massive wonders that were made by previous Peoples of Earth)

Honestly,.. its Really Hard if Not impossible to Makes Slot Machines with Symbols that are of the Same Subject yet they dont act as Part of another Slots Relevance...

feel free to add any ideas for Slots in the Comments Everyone

anything that is the collection of unknown Objects, is a Good idea!Things we Enjoy like Deserts and Candy's! Things We Believe that some may Have Different Outcomes of Opinions yet All are Good in the end!