Really well executed art style. And the popup book effect really sold it. I loved that even the ground coverings were water color. In terms of time it probably was a stretch, but would love to see what enemies would look like rendered in this style.
Minor visual annoyance was the occasional z-fighting and that the player character felt like it was missing either a mesh or that the normals were flipped.
It was an interesting choice to create a tower defense in a single dimension. Think the design as it stands is a little tricky as there is very little incentive to move between nodes along the line, feels like the optimum strategy right now is to continue to expand the frontier. Maybe adding an additional dimension or branching would help solve the problem, or failing that, at least providing reasons to go back and forth between nodes. Dialing in the feeling that you're successfully spinning plates is where I'd imagine a lot of the design potential lies.
Just on controls, found it a bit frustrating that space serves a dual purpose, since sometimes radishes were too near towers and so I'd accidentally spend my hard earned radishes.