This "coming soon" page is meant to be mysterious, dark, exciting, epic, like a poster or trailer to something amazing.
The background should be black or dark coloured, blended in with a pattern, maybe a maze/padlocks/abstract.
The theme should be complimentary to the company logo but not be overpowering. If it can be made similar to a movie poster that might be interesting too, like the INCEPTION poster I've attached.
I'm actually open to new ideas so please make it look amazing and try and do something that you think I might like. As it's actually a real-life emulation of a computer game, I don't mind the theme to be computer games like either.
You may use stock images for graphics/patterns if they have no copyright issues.