Really nice and smooth game play! Especially for casual players, since it's super easy to get and play.
The add-ons, like the rotating knife add to the fun.
It would be nice to have some info initially that one has to collect a certain number of veggies for an upgrade, but on the other hand – it becomes clear quite soon
The graphics and the sound are a bit repetitive and simple: While the veggies are cute, the background is a bit bleak and boring. The music is very repetitive and I would probably turn it off after a while. You could change the music pieces, maybe simply rotate them. Ideally, the music would "heat up" when there are many enemies on the map, but that's more difficult to implement.
Good job! :)