Thanks, I wasn't sure deflicker got off with this one (picture is already a lot better than games like Twilight Princess, so it's harder to tell), and apparently it didn't.That's one of the games that uses MetaFortress, so most of them can't be patched.
You can make Kirby's Return to Dreamland work by placing the attached file on the root of your SD card.
I'll make sure to try your patch!