Here is an Platformer Engine (I've used some parts of @Griffpatch's Platformer Tutorials: https://www.youtube.com/playlist?list=PLy4zsTUHwGJIATydhFeZa5pspLZR7yE__ ) with also an small example too. You can design your own levels with this here. movement are the arrow keys.
Use with Credits. Made for @Arrow577, he has ordered at the Scratch Ebay Shop. (Posted here: https://scratch.mit.edu/discuss/post/8418502/ )