There are more than enough ringsels in the game to upgrade fully, and most of them are located in obvious spots in harder to reach areas of the platforming sections. If you don't feel like finding them all, you can make it even easier by saving your game once you have enough to unlock level 5 defense, earning this achievement, then reloading your game and saving up until you can get level 5 attack for:
Doing this will not prevent you from getting the 0 point
This achievement is like the platinum trophy for the Playstation. It doesn't matter if your save file never has both level 5 attack and defense at the same time, you'll still unlock that at the end once you have every other achievment.