I have a project called Mod Sim (https://scratch.mit.edu/projects/542891835/) that I'm making. The idea is simple: It starts off with a square on a background, and that's all. You then “download” mods from a store in-game, and these change the game. You can also get mods that contain “viruses”, which you then have to work to get rid of. (this is to make it like real mods, which contain malware a lot of the time.). The issue is, I've kind of run out of ideas for more mods. So if anybody would like to help make more for it, that would be great. I'm afraid that there's quite a lot of code, but if you need me to explain any part of it, I will.
As for how to help: If you make a remix of the project, and in the instructions of the project explain what you've added, I'll look through the code to find where you've changed, I'll drag those blocks to my backpack, and then add them to the main project. You're name will be added in the notes, or, if I run out of room, I'll add an in-game credits section.