It's been three days since the jam started and I am not able to come up with an idea based on the theme.Now, it's only 3 days left and I really do want to participate in the jam. Really disappointed with myself.

Hey dont be disappointed with yourself this is a jam. It's always about having fun and not getting disappointed. Even if you dont have an idea just make anything or at least participate. Jams are used to improve your confidence. Maybe right now you won't get any idea but maybe afterwards u will. 

Same. I think the theme doesn't leave too much to the imagination, it is very specific. I could make it about rewinding time but I bet that's what most people are doing. 

Besides that, I couldn't come up with an idea that would make for fun gameplay. Maybe I'm not in the mood. 

Guess I'm gonna sit this one out   :(

dude ,  The best place i get idea is from the restroom . Use the tip Hahahahaha.

You can try coming up with a story-related "rewind", rather than gameplay related "rewind", that way you can make any game you want while sticking to the theme. From my experience from previous game jams, I saw some games which had nothing to do with the theme, but are amazing! So don't feel so hampered down by the theme.

Ideas are only 10% of jam games. You can take a terrible idea and turn it into a great and fun game, but you can also take a great idea and turn it into a terrible game. You definitely have enough time to participate, believe in yourself

try thinking of a simple puzzle game, like snake or whatever and making it work, i have picked simon says, the 80's electronic game so please don't pick that :)