Hi, first, may I ask for you to rerelease Galactic Wars for free? It would be great for those of us who haven't played it.
As for new ideas, you should definitely do more mysteries & detective stories, anything with more different puzzles would be awesome.
Anything underwater as well, something like Finding Nemo would be great.
Super Mario - I think the story would be perfect for this.
Anything fairytale or with more magic. There was an old fairytale that I loved, it was about a prince cursed to be a bear & than the girl has to go & save him, and she has to do all these quests, something like that, I looked it up & seems to be called East of the Sun, West of the Moon, I think it would be great for Diggy.
Something like Indiana Jones, The Librarian/s, The Mummy, The Scorpion King, Stargate, Prince of Persia (unless you've already done them).
I do like the idea for Australia above, maybe do something like that for different continents & countries.
Neil Gaiman's Stardust, Coraline & The Graveyard Book
The Nightmare Before Christmas
How to Train Your Dragon
Asterix & Obelix
Zorro
Charlie & the Chocolate Factory
Wreck-it Ralph
Resident Evil
Underworld
The Princess Bride
The Princess & the Goblin
Mr. Bean
Despicable Me
Bunnicula
Ice Age
Monsters, Inc
The Song of the Sea
The Hitchhiker's Guide to the Galaxy
The Three Musketeers & The Count of Monte Cristo
Diana Wynne Jones's Howl's Moving Castle, Castle in the Air & House of Many Ways - these would be perfect for Diggy, I can't believe I almost forgot about them.
I wouldn't mind more horror & supernatural events.
Also, it would be fun to play an event for every season, like a spring event, summer event, etc, not connected to the holidays, though I do love the holiday events.
Also, I'd love more repeatables & recipes in the events. You can make the cooking time of the recipes to be longer, and than the energy to be bigger, or even make those segmented if it's possible.