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