That helped SteelFin plus this email reply from Stardock Sales:
The game can only be purchased from our Store page but when the game releases it will be added to your Steam account and you'll be able to play it on there.
The pre-orders go directly through our Store page but the game will require Steamworks to be able to play it.
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Evan Kathawa
Technical Adviser
Not happy about the Steam requirements, have some bad blood between them and me and problems with their service that they didn't want to support or help me with an issue caused by their system, just take my money was all... (told to live with my loss until I had outside mediation step in) Just glad that Stardock gets my money directly in this case so will live with their (Stardock) decision for distribution.