I've been experimenting with platformers without having to use My Blocks. It sort of doesn't work, but just imagine that all of the platforms are water and you float to the top. The jump looks pretty bad, too, but it's easy code. Remix and make it look better! This kind looks really bad.
I made this to show that you CAN make a platformer really easy, although it doesn't look good. It's only so you can understand the gravity of a usual platformer. Just so you know, there are a lot better platformers out there, so don't waste too much of your time on this one.