Thanks for taking the time to do a Linux build. It definitely runs better.
I don't do many modern fighting games having mostly played SNES/Genesis era ones, though my wife plays modern Soul Caliber, so those will be the baseline for our thoughts.
I pulled up the practice mode and messed around a bit, trying various moves from the move list. The moves seem good. We like that some have combos or secondary moves you can trigger while the primary is active, such as launching the spinning spike wheel. The biggest thing that stands out is that it still feels a bit laggy. Its like the characters pause just a little too long between moves. I'm not sure the best way to fix that feel. Maybe there is a way to trim down any final delay at the end of the move, or if there is another input ready at the end of the current animation, create a quicker transition from one move into the next. The thing that comes to mind is Coyote Time. Letting the player jump even though they have actually already gone off the edge. It isn't realistic, but in many cases it makes the player feel better and makes for a more fun game. It feels like the characters don't react fast enough, and that feeling is something we think is important for an enjoyable experience with a fighting game.
I'm obviously not an expert, but I'd say there is potential for a good fighting game. If you can just fix that bit of feeling like it has a slight pause. I know the final polish and balancing of speed/responsiveness for the right feel is tough, but getting the right feel is the thing that stood out the most in our play testing.