I ask this because the first time I reached the 2nd loop on a single credit, I was pretty sure I didn't get 100% on ANY of the stages, although I usually don't really pay attention to it. Tonight I had a game where I got 100% on 1-1 and 1-5, dunno the rest... and even though I cleared the first loop on a single credit, I was denied the 2nd loop. It really surprised me (I wouldn't have beaten my old score anyway - I died a stupid stupid death on 1-4, and then died on the last boss's last form). I ended up getting 2.72 million and the stage on the high scores is listed as 2-0.
If reaching the second loop is entirely dependent on the contribution ratio, then that's really stupid. Having that be the sole factor that determines if you go on to the 2nd loop when it's such a strange system that nobody really fully understands... yeah.

This'll really kill my desire to keep playing it, I'd be enraged to have a game where I 1-lifed the first loop (hey, I came close once) and then didn't get to play the 2nd loop.