You've got a really fun foundation! And Bulbie is adorable! All you need is a little spicing up in the story department, and some more interesting levels. Some feedback would also be appreciated, because when I get hit, I don't notice (except for the hearts disappearing) Also, the enemies in the first and second level will immediately hit you when you enter.
Also, maybe I missed something, but what is the point of planting flowers vs just walking over tiles to turn them into grass? Maybe, if you decide to keep working on the game after, have plants do something like create alternate routes to complete the level