Finally had some time to work on the game. Managed to make a fruit eating script!
The mesh is deformed, collider and all, with a rather basic script (It doesn't actually take chunks out of the fruit, it just shrinks vertices towards the middle). A simple shader changes the color of the fruit depending on the distance to the center. I need to figure out something a bit more advanced if I want more irregular shaped fruit-planets.
Next up is modeling the grub and adding controls for moving it around the planets.