I think I might claim it. I've put together several runs back to back now, with little quirks here and there. But a perfect run up to the end, then decided to use a save-state, which automatically triggers "sloppy" mode for me. If I'd been playing on the real system, I'd have gone purely defensive to make sure I got the win. (My run I was cursing about actually
was on the real system, though.)
I did go through the last two stages multiple times, though, without deaths. I'm pretty much done for the night, but I know now that I could do it for sure. Assuming, you know, I don't just claim it.

Yeah,
Battletoads was tough stuff. I've also beaten
Holy Diver, which some consider even harder. And it's
definitely hard. I recommend everyone at least giving it a shot. It's actually not that poorly balanced to start with, but after Stage 3, the gloves come off.