Great idea... Loved the controls, very intuitive.
I think what most people don't seem to get is that it's normal to have some kind of learning curve in a game. It's a learning experience after all, and, the way I see it, that's the most important part of the whole deal.
It's precisely because of that discomfort we feel trying to translate the impulse to move in a certain direction to the task at hand that the game works! It was easy to overcome the difficulty in the first level, second level is daunting, because it seems twice as big. I'll definitely keep playing and will share with my students in class.
I told you it was my first pick to rate, very rewarding! I missed sounds, though. Thank you for sharing your work! Good luck in all you endeavors!
*edit> I went back after seeing other comment aand realized my sound settings were off!. Agree about the loop. Still miss some sound when you plant the plant, that would be very satisfying!