Wow! That is an awesome defense that you have assembled there! I admire your patience and dedication putting that together.
I totally agree with your points on the feedback. If I was to continue working on this current demo I would definitely work on the shooting flowers some more to balance the game and make it more fun. Readability is certainly an issue as well my pixel art skills are a work in progress in themselves so I appreciate that you stuck with it despite the graphical short comings.
Thanks very much for taking the time to try it out and for leaving your feedback!