If you look at the board at the time of this post, you'll notice my run is the only 1CC. I want to explain why this is a completely different category from a credit-fed run, and why 1CC is the actual any%.
Like many arcade games, this one has something called "rank" that scales the difficulty in-game based on your performance. As you complete levels without dying, your rank increases. More enemies appear, their AI becomes more aggressive, and bosses have their max health.
However if you die, the rank drops. Fewer enemies appear, they become less aggressive, and boss health drops. The effects of this are so significant that a credit-fed run can save minutes over my current 1CC time. That makes comparing the 2 fairly impossible.
So what does it mean to credit feed? It's when you insert a whole mess of coins into the game because you want to finish it without game over. The reason this is not the true any% is because it's not a legitimate way of completing the game.
The default life count is 2, so normally if you die twice you game over and cannot complete the game. Imagine running an old console game and using a code to give yourself 99 lives because you can't beat the game otherwise, and in doing so those extra lives let you arbitrarily beat the game minutes faster.
That being said, a lot of people just want to do casual runs and not really learn the 1CC (it's very demanding). That's why I think Credit Feeding should be its own category. Going back to what I said about rank, 1CC and credit feeding are way too different and showing both on the same category is confusing and gives people a false representation of what speed running the game should look like.
Not many people play this game due to the difficulty in beating it on 1 credit. For those who decide they want to learn to speed run the game, you'll first need to learn how to 1CC it.
This is something that I've been doing for years, so for any questions you can contact me either here or (more reliably) send me a whisper on Twitch. My channel there is twitch.tv/ihdl, and you can reach me there pretty easily as I'm online often.