That’s no moon — it’s a gigantic update to a video game.

Microsoft is preparing to release Halo: Master Chief Collection on Nov. 11, but the disc you can buy that day won’t have everything that you need to fully enjoy some sci-fi first-person shooting. Instead, you’ll need to get online and download a 20GB patch that enables new features and “multiplayer content,” according to Microsoft (via Kotaku).

This means you’ll need to install the 45GB Blu-ray Halo disc on your Xbox One, and then you’ll need to wait while another 20 gigs downloads and installs on your system. You can avoid this situation by purchasing the new Halo omnibus digitally, which gives you the option to pre-install the entire game and the update. That content will then all unlock at midnight on launch day.

“From the start, our philosophy has been to give Halo fans the best possible experience and not compromise the quality or features of the collection,” a Microsoft spokesperson said in a statement. “The result is that Halo: The Master Chief Collection will take up almost all of the usable space of a single Blu-ray (45 GB), and we will also issue a content update at launch that is estimated to be 20 GB. You’ll be able to start playing Campaign and more as the content is installing, with some features and multiplayer content being added via the update.”

Microsoft acknowledges that the update is unusually large, but it explained that it didn’t want to “cut corners.”

“This ensures that you are getting every bit of Halo goodness we can fit in,” Microsoft’s statement continues. “Our work is not done, however, as we continue to tune, tweak, and optimize the online experience to ensure a smooth multiplayer launch. This will continue right up until launch day.”

Digital games are getting larger, which is likely one of the reasons that so many people are happily sticking with physical discs. If you a slow Internet connection or some kind of data cap, 20GB to 50 GBs every few weeks is often way too much.