Thank you for your feedback! I can add a difficulty menu to decrease how many enemies come in at one time, but I don't know if that would be against the rules of the game jam, since it is not over yet :(
While it is very challenging as it is, you can make use of the first couple of seconds planting sapplings. Then when things get hectic, you can try and hit one of the boxes on the middle-side areas.
Thanks again!