I'll say this. You're speaking as if you're already very committed to this particular game conceived in this particular way, and I would just ask why?
It's a three day game jam. What you're proposing is like getting married after one date.
You tried this out. Certain parts of it didn't work. You've still got the assets, the animation rigging, the sets, the engine, all of that. You're not married to it. You can scrap the whole thing if you want, and you're still totally fine. You can give it to ten different playtesters, see what they think, and if they say the same things I said, you can just kill the thing with no longterm harm done.
The only time you really commit to producing a game is when it starts to get traction from players, when playtesters consistently play it for more than a few hours at a time, when a few of them get all the way through the game and ask you for more of where that came from. Until then, you're just trying stuff out. You're not married to it.