I recomend to play this project if you want make remix. https://scratch.mit.edu/projects/723881149/ Original project -https://scratch.mit.edu/projects/544248133/ Concept should have interesting unit and must have troop card(if unit can shoot must have projectiles). Unit can be a troop, tower/defender or barracks. Go inside of project.
I added example characteristics in 'help' sprite + stuffs from BSSV beta 1.9