The Theme is Undead. Due to it being that time of the year, I thought something Halloween based would be good, and your goal being to make a "Survival" game, the theme Undead, could be interesting. This is however a very broad theme and allows you to make really anything you want, which won't always be the case for this jam, but being the first one in a while I thought it would be good to start with something like this.
The Theme is now on the Game Jam page.
I saw some people talking about it in the comments, and would like to mention that teams on any size are allowed in this jam, the main goal is to have fun.
In case you missed it please go to this thread, read it and vote on the poll, it would be very helpful to hear your thoughts - https://itch.io/jam/survive-the-game-jam-4/topic/152710/what-to-do-with-the-yout...