Text adventure engine for unity

Hi all

Does anyone know of a text adventure engine for unity? I want to tinker with a text adventure, rather than interactive fiction. That is, making the player type "go north" etc rather than selecting on a few options.

I've been using Inform7 to tinker but I like unity and feel it might be easier to stick with a more formal structure rather than the "natural" language of Inform7.

Also would like unity for the background layout and effects.

Olly