Hi,
Did you try the new demo on Steam ? :)
https://store.steampowered.com/app/1769270/Spikair_Volleyball/
For the online, we want to try but online for fast-paced games isn't easy too implement :3
Viewing post in Spikair Volleyball (Alpha) comments
Yes I downloaded it yesterday and game is feeling good, I'm pretty sure you will find online solution. Isn' it like tennis games ? playing vs AI becomes boring but this is only my opinion many people like playing AI.
For sure I will be big fan once online. I'm 40 yo so bringing friends to home and play local is no more a practice