Cute visuals,
Fun idea, I think for a jam game you probably wan to air on the side of making the game a little too easy that too hard. I get it making a tutorial isn't always with in the time budget, so making it easy to play lets people get the idea more easily.
I wish I had a little more control of where I can place the turrents, and there wasn't friendly fire as I got kiled by myself a bit XD.
But definitely a really solid idea visually appealing game there.
Well done.