What are the key differences between Injustice: Gods Among Us and Injustice 2?

Injustice 2 builds upon the foundation of the first game with improved graphics, expanded roster of heroes and villains, and a more refined combat system. It introduces new game modes like 'Run' and 'Zest' alongside the classic ones. Injustice 2 also features a more branching story with multiple endings depending on player choices.