I should probably have mentioned that this is not the first time I'm making a game.

The last time I made one is about 10 years ago, but I have some experience in how to make it work, both in team play and solo. As for story: I've got something in mind right now but I would like to keep that quiet for two reasons: first and foremost, the rest of the team needs to agree once the team is complete. Second, I don't want to spoil the story too much for the people who will be playing it.