Oh god I know those feels. Pretty sure I never finished it. Actually, there are a lot of scrolling shooters like that for me.

I love the genre, and there was a point where along with RPGs, they were pretty much all I played. But there aren't that many I've actually finished. I usually clear the opening levels with relative ease, and then get stuck on the second to last or last level. There often seems to come a point where the amount of work required to finish the game for a player of my skill level doesn't really seem worth the reward of actually finishing it. :'D