What do you mean by "Meta"?

By meta, I mean that the game makes the user thinks about the actions they've whether it's while they're playing or at the end of the game. Take Undertale's genocide route for example.

When can I work on my game?

Brainstorming, writing, non-technical things, etc can be worked on before submissions are enabled. But the technical things (code, graphics, etc) must be worked on from The 31st of October, to the 18th of November

When can I vote?

From November 18th to December 1st.

Can I work in a team?

Of course, although I wouldn't recommend a team bigger than 5.

Is there a specific OS/device I have to export it to?

Nope! The voting is public. I personally will be using a Windows 10 PC.

Is there rewards?

Not yet, atleast.