This game has very hard to reproduce but game-breaking glitches. Maybe it is possible to get a credits warp or level warp from them?
Check out the descriptions of my videos for savestates you can open in shmupmame. For example, load this savestate https://www.dropbox.com/s/1szywtvsi90nf7z/0.sta?dl=0 with rom omegaf if you want to try and get the debug menu yourself (you'll want to use insert to fastforward a lot, probably)
For me the glitch started like this:
Link to video
And by loading state and running it by again with different input I get different results with low probability, including a debug menu and a debug frame advance mode:
Link to videoLink to video
Unrelated to me, a different person discovered a similar glitch that froze the game, displayed ? on the screen, then warped them from stage 2 to stage 1:
Link to video
