Board Thread:Questions and Answers/@comment-1534174-20200329220601/@comment-35248429-20200330200717

The anime left out a few lines of dialogue 30 episodes previously that confirmed that you can in fact log in with the Amusphere.

Basically as told to you by Gabriel when Vassago brings it up, you can't record things seen within the Underworld or even observe them without logging in with the STL. Yet RATH is clearly observing and recording what's going on in there albiet at 1000x speed. That's because Underworld is operating on a dual layer system, the top layer is the STL, but the bottom layer is using the SEED package. Which allows them to observe and record, but at the graphical fidelity of a normal VR game and not the life like realism of logging in with an STL.

That lower level system since it's basically a world from the SEED can be logged into just like any other game with an Amusphere, and even allows account conversion. The graphcial fidelity will be less, you have to have the time dilation set to 1:1 (hence why Critter does this) and you can't do things like Incarnation as you're not connected to the Main Visualizer.