I'm not entirely sure, but it probably features versions of Dipper, Mabel, and other main characters from Gravity Falls, just with different personalities or roles in this reverse version.
It's a unique take on the Gravity Falls universe. It likely involves an alternate version of the story, with different character dynamics and plotlines in a visual novel format.
One common theme is the clash of good and evil. Since Reverse Falls is often depicted as a more sinister version of Gravity Falls, when the two meet, there's a lot of conflict between the good-natured characters from Gravity Falls and the more devious ones from Reverse Falls.
Well, 'gravity falls reverse visual novel' could potentially be a new take on the Gravity Falls universe. It might mean that the plot progresses in a reverse chronological order compared to the original show. For example, instead of starting with Dipper and Mabel arriving in Gravity Falls, it could start with the end of their adventures and work backwards, showing how they got to that point. It could also reverse the roles of some characters or the nature of the mysteries they face.
One idea could be that the characters from Reverse Falls accidentally cross over into the Gravity Falls universe. They might initially be seen as threats by the Gravity Falls gang, but then they realize they have to work together to solve a mystery that threatens both universes. For example, a powerful and ancient evil that can only be defeated if they combine their unique skills and knowledge.
Definitely Dipper and Mabel from both universes. Their different personalities in Reverse Falls and Gravity Falls make for really interesting interactions. Bill Cipher is also a popular choice. His chaotic nature can add a lot of drama, especially when he interacts with the characters from the other universe.
One of the most interesting plot twists could be when the characters from Gravity Falls and Reverse Falls have to team up against a common enemy they didn't expect. For example, a new supernatural force that threatens both their worlds. This would force them to put aside their differences and work together, which is a big change considering the nature of the two settings.
To create a compelling character interaction, think about the goals of the characters. In a crossover, a character from Gravity Falls might be trying to save their world, while a Reverse Falls character could be trying to take over the other world. When they meet, there will be conflict and negotiation. Let their different motives drive the conversation and actions. Also, use their unique abilities or powers in the interaction. If one can read minds and the other can manipulate shadows, how do those abilities play off each other when they interact? It can lead to really interesting scenes.
One great 'Gravity Falls meets Reverse Falls' fanfiction is 'The Alternate Encounter'. It has an interesting plot where the characters from both universes interact in unexpected ways. The author does a great job of capturing the essence of both Gravity Falls and Reverse Falls.
I'm not sure where you can specifically find it. It might be available on some fan - made game platforms or indie game websites. But you'll have to do some searching around.