I tried to build and run your github version and all that came out was a black screen with music(and controls - if i press enter i can start and shoot and stuff. Even got past first 2 barriers -blindfold ):
That is probably cause of my archaic computer though
Now at chili's version I was actually able to play but there is a bug where game crashes when i reach the boss:
Besides that there is a bug where animation of black hole sucking you in starts but if you dodge the second animation by moving to the side than black hole continues to float with you along the screen and music breaks.
Also inside the black hole there is sometimes no pattern. And then there is a pattern where you can just float through in a straight line except for the last obstacle.
I would also suggest to make bullet counter for destroying the violet ship lower.