The way I see it, the mechanics can cover games as simple as Flappy Bird to games as complex as Real-Time Strategies. But the criteria "Gameplay Creativity" is the real limiter.
I could've also commit with the "No mouse position" games since they suddenly start popping in my head, but it's too late to turn back for me now.
In any case, this Jam is great for beginners to get their feet wet, and that's what I like about it.