Congrats on reaching the extra level and being one door away from finishing the alpha-version. Actually that's a door without a button so the only way to pass through it is to wait till the moving platform pushes it up and pass quickly before its closed again. I am sorry that this level is a bit unfair; it is too hard even for me, I fail at it 90% of the time. That is why I added it as an extra level that is not a prerequisite to any other level. It was my brother's suggestion @yassinzak so feel free to blame him as much as you want :D