Okay so ive played the game for probably more than 5 hours total now and I still havent figured out how to block properly. What I did notice though, is that hitting into the opponent's block is often a free point, as the trajectory the ball follows after hitting the block is unpredictable even for the ai. I would just reccomend changing how blocking works or at least just making it more clear what you have to do but whatever its your game
(Also idk if you already planned on adding this but more keyboard support would be cool, especially being able to aim with the mouse instead of directionnal keys. Adding more rebinding options would be cool aswell, like sepparating the "jumping" and "spiking" actions to 2 different keys, same for "setting" and "bumping", I think it could add more depth)