They’re not mincing words, either. That’s the official title. It’s Marvel Heroes’ “biggest update ever.”
Virtually every aspect of the game has changed in some way, shape, or form. We should start with the most basic: there’s a Lunar New Year event. Of course you’ll be way too distracted by all the game system changes to really appreciate an event, but it’s there.
Hero powers have been completely overhauled across the board, and they’ve added a talent system similar to other games, and a difficulty slider to make it easier to customize the game to your preference. Chapters 2, 3, 5, & 6 have been completely revamped with new areas and boss fights. And the omega system has been streamlined into a infinity system.
That’s really just the tip of the iceberg. For more information, feel free to peruse the gargantuan patch notes on the forums.