You are the coloured rectangle. Press space to change colour. Use arrow keys or WAD to move and avoid yellow.
The key is from the library. I created Blocky. I used Griffpatch's platformer tutorial for the platformer script. You can find it here: https://scratch.mit.edu/projects/67727504/ I also used Tralla_kid's scrolling tutorial: https://scratch.mit.edu/projects/597191/ I would really recommend giving them both a go.
