Love the concept; taking care of a garden but not having enough time. Something we can all relate to!
I can see many ways you could add new mechanisms for new levels: trim the hedge maze, fight a creeping vine that blocks your movement, dandelions that go to seed and spread if you don't get to them in time, etc. I'm hoping to see more of this game soon!
I do wish I could move diagonally though, found myself often pressing the buttons to do so without thinking about it.
The animations for all the plants are cute and add a lot of character to the game.