Nothing beyond the initiation stage of development.
In other words, just concepts. It doesn't sound safe to be actively working on multiple projects without securing that one meets certain standards.
Yeah that's the smartest path. I should do that too, but I think I've finished every prototype I've made so far, though I give less effort the more I feel it's not so worth it.
I like to make art, maybe that's why I go after every prototype, and the project may take new directions the more I mess with it.