First, decide which universe you want to crossover with. Then, think about how the goose's personality and actions would fit into that new world. For example, if it's a crossover with a fantasy world, the goose might be seen as a strange magical creature.
A crossover with Minecraft would also be cool. The goose could waddle into the blocky world, disrupt the building projects of the players. It might steal their resources like diamonds or iron, and peck at the creepers just for fun.
The 'untitled goose game' is about a naughty goose causing mischief in a village. The goose goes around stealing items, honking at villagers, and generally disrupting the peaceful village life.
One interesting plot could be the goose forming an unlikely friendship with another animal in the village. For example, the goose and the cat team up to prank the villagers in a more elaborate way than the goose could do alone.
The goose itself is obviously a very popular character as the main troublemaker. People often write about its mischievous antics in great detail.
The main character is the goose, of course. And there are various villagers like the gardener, the boy, the shopkeeper, etc. who interact with the goose.
First, choose the games you want to crossover. Then, study the lore, characters, and settings of each game well. After that, think of an interesting plot that can bring these elements together. For example, if it's a crossover between a racing game and an adventure game, you could have a plot where the racer gets lost in the adventure world and has to use their racing skills to survive.
The village dog could be a main character too. It could be constantly chasing the goose or getting tricked by the goose into chasing its own tail. It might also have a soft side and end up befriending the goose in an unexpected turn of events.
A simple plot could be the goose getting lost in a new area of the village that has never been explored before. It then has to find its way back while causing chaos along the way.
First, decide which other universe you want to cross 'Game of Thrones' with. Then, research both universes thoroughly. For example, if it's with 'Doctor Who', know the rules of time travel in 'Doctor Who' and the politics in 'Game of Thrones'. Next, create a strong plot that ties the two together. Maybe the Doctor lands in Westeros during a crucial battle.
Begin by establishing the setting clearly. If it's a Joker crossover with a horror universe, describe how Gotham starts to take on elements of that horror world. Then, introduce the Joker in a way that makes sense in this new context. Maybe he's intrigued by the new horrors or sees an opportunity to create more chaos. You also need to consider the characterizations and how they will interact. The Joker's maniacal nature might clash or blend in unexpected ways with the other characters.