Thank you for the feedback!
I appreciate your time writing this out and pointing out the positive and negatives! I am actively addressing the issues you've pointed out, including enhancing animations, improving player feedback, and introducing tower upgrades. I will be fixing them on the next update as I am more focused on fixing the major bugs and issues that still have been fixed yet.
You are able to sell the turrets that you have placed by righting clicking on the placed turret and receiving half of your money back.
Again, thank you for your time on playtesting on my game and I hope the next update impresses you!