Well, being the star in Project Sekai's story means facing unique challenges and having the chance to shine. You get to make important decisions and shape the outcome of the story.
Yes. Platform availability can vary depending on licensing and technical considerations. However, the goal is usually to reach as wide an audience as possible. So, you can expect to find sekai project visual novels on platforms where there is a significant demand for this genre, such as Steam for PC, and sometimes on Nintendo Switch as well.
There is also 'Dies irae'. It features a deep and immersive storyline, with a lot of elements that keep the players hooked, such as its world - building, character development, and the various plot twists throughout the game.
No, 'Billions' is mostly a creation of the writers' imagination. It weaves a compelling narrative but doesn't draw from a single real-life account. However, it might incorporate common themes and scenarios found in the business world.