After battling the normal .NET rubbish I finally got the launcher to run.
If I try and run Horizons I get to the generating planet bit ( after the shaders ) then it maxes out my laptop for 5-10mins until I reboot ( because machine is completely unresponsive, including ctrl-alt-f1 for console or ctrl-alt-esc to kill the program or ctrl-alt-del ).
If I try and run non-Horizons I get the video and music but then it crashes, sometimes it doesn't crash and I get a little further, even to the menu, but it's unresponsive.
I did the VC2017 update.
and I'm set to Windows 7.
kubuntu 18.04
wine 4.0rc1
nvidia 390.87 ( GTX 1050TI - it's a gaming laptop )
I'll keep fighting with it tomorrow for a bit - it's 2am now

Not helped by the fact it looks like the servers are still having issues, not that I've got close to actually connecting to one yet.