1) Define your core loop

http://getting2alpha.com/downloads/Getting2Alpha_Breakthrough_3-Game-Thinking-Blueprint.pdf (TL;DR - At least read page 8!)This is the repeating activity that your customers carry out that creates value. It is also an activity that they can “improve at” when using your product. I would highly recommend reading / watching the extensive list of material that Amy Jo Kim has created. My only additional comments are that this “step” is focused on the business (after all it is “core”) rather than the technology. It can also be relatively tricky to pin down in start-ups, and because of this it should be tested early! It might also take several iterations to get right - in fact it might not be until several of your next minimums have been created and tested before you settle on a final core loop.