Play and tweak your creations. In test mode you can grab and possess and so on as you can in play mode, but you can also use tweak menus as you can in edit mode.
Changes you make to tweaks will persist when you rewind. Changes to sculptures will not. This is about tweaking your gadgets rather than editing your scene.
The Dreams User Guide is a work-in-progress. Keep an eye out for updates as we add more learning resources and articles over time.