Hmm, it seems there is one more interesting option. Soon releases Blade Strangers for PS4 and Switch. It features fighters from Gunvolt, Cave Story, Code of Princess (actually a lot characters from that game), Binding of Isaac, Shovel Knight and some stuff I don't recognize. Actually it looks quite cool. I like 2D anime style fighters, as they tend to be over the top. Whatever, as it contains characters from multiple games including Shovel Knight, I thought that might also be interesting to you.
Was hoping for more party-like game but this looks good. Thanks!