I'm interested in participating, but my story deals with mature themes, including psychological violence and a strong twist that may be disturbing to some readers. While an adult audience would likely understand the context, I'm concerned that younger participants or viewers might be affected. Would a game with mature themes be out of place in this Jam?"

Things that are explicitly banned from the competition are listed on the page.  Otherwise you need descriptive content warnings on your submissions.

If you want a more concrete answer, you need to tell us what you're planning on making.