That is the best part of doing game jams, after the fact you can do whatever you want with it. I can't think of a single game I've done for a jam that I haven't fixed up after the fact at least some. It's better to polish it up for future players in my opinion but that's up to you.
The only reason I wouldn’t want to update it is so I can work on another short game. I spent so long spinning my wheels getting nowhere on a game I have long since lost interest in, I’m a little jaded sticking with another project. I suppose I just want to keep this ball rolling to see what happens.
But you’re right. It wouldn’t take a lot of work to make the game much better and let’s face it, reach a wider appeal.
And I owe it to myself to see this one through. It is the first game I haven’t burnt myself out on before I got to the creative stage.