What happens if you accidentally grab a mushroom or use a P wing or any other powerup. I could see if you menu'd too quickly that you could possibly grab something on accident.
I know in Ninja Gaiden for some of the restricted runs if you grab something accidentally the run is still alive but you have to take a death to clear the thing you did.
Any input appreciated =-D
If you somehow do use a mushroom, p-wing, etc. the run is unfortunately invalid. The rules are like this because we believe it's easy enough to avoid such a situation. For the menus the risk is the same as accidentally using a warp whistle in warpless, which would also invalidate the warpless run.