Good windows port.
The browser version also locked up after the story sequence every time after the first. That first time however, it only locked up when I beat Beat.
As for the Dreamcast port I'm a lazy ass who still doesn't have RGB cables or Dreamcast friendly cd-roms, so that's out of the question.
What I was able to play though seemed like mugen ass mugen, albiet with a d-tier beat. Mima's de-confirmed though, so that's a bummer.