[Revolver Koala]

Just play Santiago as if it were on Reverse and not Under Attack. If you see 9 5 7 (random example), hit 9 5 7. You'll hit all the hidden steps. I explained the Under Attack mod and why this works in my other post, but just hit the steps you see. I still suggest tapping around on the pad and watching the highlights that appear over the arrow guides just to get an idea of what Under Attack does, but what it boils down to is that you're playing on Reverse. If you're doing it right, the steps you see onscreen will scroll off as if you missed them, but you'll still be racking up perfects.

EDIT: Guatemala is annoying, you need two or more people for it. If you have four, it's totally easy, but if not it can be tricky. We used two people to clear Hong Kong and Rome, too; the chart for Fire is really easy, but it's absolutely ridiculous for one person to read without a lot of practice. There's very little margin for error; I'm not sure exactly how many steps there are, but you can't miss more than a couple steps and still pass.