Took me about 7 hrs to beat it on Easy. I don't like it enough to try any higher difficulty levels.
When I bought this, it was the top game I wanted for the system, which is why I was willing to spend as much as I did. It ended up being a big letdown. I'm guessing this would be classified as a bullet hell, something I've never played before, so I don't know what qualifies. If it is, this probably means that I would probably dislike the sub-genre. I don't like the convention of switching between black and white to avoid damage or to build up the homing laser. I dislike that there are no weapon power-ups or other weapons, just the forward shooting guns and one special homing laser attack that you need to build up to use. Everything is on one plane, so enemy craft that appear to be well below you aren't, which threw me off many times leading to deaths. The free life point requirement seems to me to be ridiculous, as, even on the most charitable setting, I never even got to half the points needed to get a free life. The game is pretty short, with only 5 levels that'll take about 30-45 min to play through. You do get more continues the longer you play, accumulating over all play sessions, so eventually, unless there is a limit (I got to 9 continues), you should be able to just plow through it even without mastering it if you're willing to just put in enough play time.
All in all, I just found it to be a boring game due to no real variety in weaponry. I never felt a sense of accomplishment when I got by any obstacle.
I found out you'll eventually get infinite continues if you play long enough. So, out of curiosity, I went back to it to get infinite continues, and, due to restarting in the same place you died when you choose to continue and the bosses having a time limit to defeat them (none of them have to actually be defeated), see if you could beat the game by literally doing nothing except choosing to continue. This is the case, so I can technically say I've beaten the game on the highest difficulty setting.