I'm going back to FN0 and replaying it. This may seem like not that much of a challenge, but I plan to completely conquer the game.
When I first played it, it was tough. I then made a breakthrough around the first boss, and ended up beating the game. After that, I replayed each level uncountable times until I thought I had mastered them. Fortunately for me, I hadn't. My main problem was cash. I kept on trying to beat the levels as quickly and efficiently as possible, not paying much attention to the passages that lead to storage rooms of cash around the levels. I liked also, especially for speed runs, being reckless with my technique, for time's sake. That way, I would lose more health than if I had cared about the hit count. This works out fine for completing levels quickly, but you shouldn't need to. Due to these, I have not gotten a good score on the scoreboards. I will fix that with this rerun.
Unfortunately for me, I don't know exactly how the scores work. I hope they always count your highest score on a level, and not the most recent. This may not last long because of school, but I'll do my best.