Twine is a great recommendation. It's easy to underestimate Twine, but its a great prototyping tool and you might be surprised by what you can do with it, especially if you have a background in web dev, CSS, and JavaScript. Here are some links worth checking out if you're thinking to use Twine:
What's possible with some basic JavaScript and CSS.
Our game for the jam is being built in Unity, but was prototyped in Twine, including the finite state machine RPG engine.
Twine also looks good on a resume.