This is the code I use when making games with platformer type physics. Ya, you can phase through walls. I made it like... a while ago. I think this is my best one yet. You are a small purple dot.. Like really small.
As for the name... Uh... it was that name for a year so I left it. My brother asked how I make some of my platformers really smooth (Unreleased games!!) Well, this is how. I just use this code.