An okay episode, largely about getting Terraphaser up and running, with the Spheres resurrecting Neomegas to do some mysterious thing involving sending energy into the ground. It also touches again on the question of whether Kanata has any goals in life, and ends with a major twist.
It occurred to me to wonder about Mitsukuni Shizuma from Trigger, the guy who crossed over from the Tiga/Dyna universe and founded GUTS-SELECT. I wondered if he remembered the events of Dyna and what the Sphere's motivation turned out to be in that universe, which could be useful to understanding them in this universe. But then I realized that Dyna was set nearly a decade later than Tiga, so if Shizuma crossed universes between the series, he wouldn't have any knowledge of that universe's Sphere. Since he was flying a Tiga-era GUTS Wing when he crossed over, that seems likely.
I still think there's a good chance we'll get a Dyna/Asuka appearance sometime later in the series, though, in which case Asuka might pass on some key information about the Sphere. Then again, maybe this universe's Sphere have a different motivation. But it does seem similar, given their efforts to prevent humanity from expanding into space.