Here is the full list of all 90 Papa's Freezeria Deluxe achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Serve all of the customers!
Earn 40 Special Recipes from customers
Serve everyone in the Romano Family Quartet
Serve all the band members of Scarlett and the Shakers
Serve an Orange Roll Delight Special to Rollie
Add Pawpaw Topping to Papa Louie's sundae
Unlock all of the Standard Mixables
Unlock all Volcano Gala toppings
Serve a Mighty Mint Special to Mayor Mallow
Earn 15 Gold Customer Awards
Unlock all of the Standard Sauce Toppings
Reach Summer
Unlock all Big Top Carnival toppings
Unlock all of the Standard Placeable Toppings
Use Cotton Candy Syrup in Mandi's sundae
Unlock all of the Standard Mix Syrups
Unlock all Easter toppings
Serve a Truffle Bomb Special to Treble
Unlock all St. Paddy's Day toppings
Reach Spring
Use Yum n' Ms in Sasha's sundae
Unlock all Valentine's Day toppings
Master 20 Special Recipes by earning 5 Stars on each
Have 10 different kinds of bubble gum in the lobby at once
Serve a Purple Pom Special to Pally
Unlock all New Year toppings
Earn 10 Silver Customer Awards
Add Shaved Mints to Edna's sundae
Unlock all of the Standard Shakers
Buy any 8 Posters from the Shop
Unlock all Christmas toppings
Serve 20 customers during Christmas wearing a Christmas Hat and Fur Parka
Use lots of musical furniture so 3 or more customers are dancing in the lobby
Reach Winter
Serve a Caramel Macchiato Special to Akari
Unlock all of the Standard Whipped Creams
Send 10 Customer Coupons to your customers
Unlock all Thanksgiving toppings
Earn 15 Special Recipes from customers
Buy any 8 Furniture items from the Shop
Serve a Cinnamon Crunch Special to Marty
Serve all of the Costumed Closers during Halloween
Serve a Wildberry Moon Special to Willow
Unlock all Halloween toppings
Master 10 Special Recipes by earning 5 Stars on each
Serve the first customer last
Serve Jojo while wearing a Turtleneck and Beret
Get 5 Blue Ribbons from Jojo the Food Critic
Buy any 50 items from the Shop
Serve 30 orders to customers in the Dining Room
Serve a Sugarplum Streusel Special to Scooter
Unlock all Maple Mornings toppings
Serve a Vanilla Swizzle Special to Liezel
Serve a Tropical Treat Special to Tony
Earn 15 Bronze Customer Awards
Serve a Red Velvet Cake Special to Kingsley
Serve Roy while wearing a Pizzeria Polo and Pizzeria Cap
Reach Autumn
Receive your wages on four Pay Days
Buy any 4 Flooring or Wallpaper from the Shop
Serve a Chocolate Creameo Special to Captain Cori
Serve 100 customers while wearing clothing that matches the season
Dress your Chef and Driver in the exact same outfit but with different colors
Buy any 8 Clothing items from the Shop
Buy all of the Upgrades in the Shop
Don't spend any money in the Shop for 7 days
Serve 20 delivery orders to customers
Unlock all Portallini Feast toppings
Earn 5 Bronze Customer Awards
Earn 5 Prizes or more in each of Foodini's Mini-Games
Earn a Prize in each of Foodini's Mini-Games
Grab 250 coins while playing Papa's Raceway
Change your worker's shirt, pants, hat, jacket, and shoes.
Earn 5 Special Recipes from customers
Get a Perfect Score on 30 orders
Add Cloudberries to Nevada's sundae
Unlock all Starlight Jubilee toppings
Serve any 10 sundaes from the Food Truck
Lure 3 regular customers to the Food Truck by preparing their normal order
Leave four sundaes on blenders at the end of the day
Have Quinn's order ready when she arrives and serve immediately
Wear a shirt, belt, jacket, pants, hat, and shoes to match the current holiday
Get a 100% Topping Score on 20 orders
Have Kahuna's order ready when he arrives and serve immediately
Master a Special Recipe by earning 5 Special Stars
Win a Rare Bonus Prize in a Mini-Game by earning a Star Medal
Get a 100% Build Score on 20 orders
Earn 3 Special Stars when serving Today's Special
Get a 100% Mix Score on 20 orders
Get a 100% Waiting Score on 20 orders