IF YOU WANT TO USE THIS ENGINE IT HAS TO BE A REMIX This is my easy to use scrolling platformer engine! All you have to do is draw your level, mabye change the player (if you change his shape or size you might need to check the player collision box and make sure it is only where you want the player to detect he is on the ground) and then you are done! Red parts are deadly (colour 0 saturation 100 brightness 100). Not all colours are collidable, you will have to look in the player collision script to see the collidable colours.
If you want a proper game that i made with this code, then here it is: https://scratch.mit.edu/projects/527236323/ it has over 4000 blocks and is a very fun game. Just me but i did use a griffpatch tutorial for top down scrolling but i have obviously changed it so much that you cant even tell. I only used that tutorial for a very small part of the game most of it is my own code.