"Angry Birds!" shouts an excited small boy as he careers around the corner and stands in front of the fenced-off area. The sign on the fence says the new play area doesn't open until next week. Parents explain this to their disappointed children. Some of the adults look sad too. "I'm addicted to Angry Birds," says Terry Lalton, a recovery driver from Doncaster, who is here with his children and extended family.

"This looks quite good. They've got the catapult [a reference to the game]." "It looks fantastic," says one of the small boys with him. Will they come back when it opens? "I hope so," he says. I have already been on the slide and to the top of the climbing frame. I feel smug.

Sundown Adventureland, an attraction in the Nottinghamshire countryside, is home to the first Angry Birds theme park in the UK. There is already one in Finland (and an unofficial park in China), and the company licensed to make the equipment says it is looking at other sites.

Angry Birds started as a mobile phone app – if you are not one of the 200 million monthly users, it's a game where you catapult birds at egg-stealing pigs – and in March, Apple revealed it was the most popular paid app ever. Last year, Rovio, the Finnish company that created the game, reported revenues of £60.8m – nearly a third comes from merchandising. "I've got it on my iPad," says Mrs Rhodes, Sundown's 83-year-old owner. "My grandson put it on for me when it first came out and I never bothered with it, but when this came up I had a go."

What is the appeal? "The birds look strong and fearless," says eight-year-old Reece Beardsaw, who is looking through the fence at the new playground. "They're wicked." His mum adds that he doesn't play the game but he likes the characters – he has Angry Birds branded clothing and stuffed toys at home.

Whereas the game also has an adult fanbase – David Cameron is a big fan, as are Salman Rushdie and Jon Hamm– the playground is aimed at the under-10s. An Angry Birds ride is planned, as well as a small rollercoaster, but these are some way off. For now, young fans will have to make do with a selection of exciting, but fairly standard, branded playground equipment.

Sundown Adventureland's newest attracton might be birds, but it all started with a monkey. Rhodes bought one in a Worksop pet shop shortly after she and her husband John moved to a bungalow, named Sundown, in 1954. They already had chickens, goats and a donkey, but it was the monkey – very soon to be joined by more, as well as a bush baby, flying squirrels and raccoons – that made the Rhodeses think they could open their menagerie to visitors to make a bit of extra money. The bungalow came with two acres but they gradually bought more parcels of land from a local farmer until eventually Sundown became the 30-acre site it is today.

The place is charming. Aimed at young children, there are gentle rides, miniature villages to explore, and a number of really quite strange models of people and animals – in the farm area, a farmer mannequin looks suspiciously like Des Lynam and the characters in the Wizard of Oz Zone will haunt me for life.

To cynical adult eyes, parts of it seem tatty, but every child I saw looked delighted. It feels like quite an innocent place, where inspiration comes from classic fairytales and legends, not big branded moneyspinners. Angry Birds has catapulted itself right into the middle of it.