As you can see from the image, some aspects are complete and ready to go while others need a lot more work.
There were a couple of tasks to get to this point:
Getting set-up as a Microsoft partner. This is relatively straight-forward although every time I use their site it tells me that my "tax status" is invalid and I can't get paid until I fix it. So I fix it - one page says I'm "good to go"; the overview still says error with tax info.
Registering my product name with Partner Centre. The only hiccup here was that I couldn't use "Gem Smash" as "Gem Smashers" has already been used - hence, I'm now calling it "Gem Smash 2019". I had to tweak some art for this, but it didn't take long.
Initiating a submission. There's a wonderful tick box questionnaire in this process which asks questions like "does your App contain swastikas?" and "does your App criticise Korea?" No issues here :).
Prepping the App in Visual Studio for the Store. This was quite painful. All the external facing art (logos, icons, splash screens, tiles etc.) have size limits on them, which are enforced by the build process. These limits are not at all generous in this day and age (~200k). It took quite a while to work though my larger assets (mainly changing pixel formats) until they were all acceptable.
Microsoft App Verification. This happens automatically when you upload the App to the Store. I was quite concerned about this step, mainly as I didn't know what they checked for. It was largely to get an early read on any issues from this process that I started the submission process (the App isn't finished!). However, we passed first time.
So, now it's back to the code to get the last features in, so I can do this for real.