The developer estimates roughly 30–40 hours for STAR WARS Zero Company’s main story. That is an estimate from the studio, not an independently measured average or a completionist target. The campaign follows Hawks and an unconventional company near the end of the Clone Wars.
Source: EA · Q&AEA · Zero Company
The premise without major spoilers
Zero Company is drawn into a conflict with Kundri Fathom and the Infinite Coil, a Separatist-aligned cult. The official story setup describes a shadow plague threatening the galaxy. Hawks, a former Republic officer, leads a group of operators whose backgrounds do not fit a conventional military unit.
The campaign combines turn-based squad combat with management and interactions at The Den. This overview covers the announced premise rather than revealing an ending or claiming a mission-by-mission account.
Source: EA · Zero CompanyStarWars.com · CastStarWars.com · Trailer
How to interpret the 30–40 hour estimate
The number applies to the developer’s expectation for the main story. Your choices about tactical planning, optional opportunities, dialogue and retries can affect your own experience. Do not read it as a guaranteed time, a full-completion measurement or a benchmark for every difficulty setting.
If you are comparing the game with other tactics titles, use the estimate as broad planning information. There is no reason to turn it into a more precise average that the official statement does not provide.
Source: EA · Q&A
Is the story branching?
EA describes a mostly linear main plot with a shared core ending. Team composition and companion outcomes can change the experience around that structure. Those variations should not be rewritten as a promise of an unlimited branching campaign or multiple entirely separate main stories.
The company you build still matters to the campaign’s personal and tactical experience. Different operators bring their own backgrounds and talents, and the roster can change how you approach encounters. For a spoiler-light introduction to those characters, see the company roster.
Source: EA · Q&AEA · Gameplay
New Game Plus and replaying
New Game Plus is not included at launch according to EA’s Q&A. Replay and progression can make some customization options available, but that is not the same as carrying a fully developed company into a New Game Plus mode.
You can consider a different team or approach on another playthrough without assuming a specific carryover system. Check later official announcements before treating a launch feature statement as a permanent promise about future updates.