Thank you so much for your great feedback!
Most of the bugs you mentioned we are already aware of, but we just had to publish it now as a first draft due to a university deadline. So we will try to fix them for the next Version.
You are right our game should have a pause button and more visible explanations.
We worked mostly on essential parts of the project to get it playable in general. We will try to improve the feeling and the feedback of the game. We hope to get more sounds, animations, and effects into the game. Also, we are currently working on two new towers with individual mechanics.
We would appreciate it if you follow us along on our road to finishing the game. We hope you can give us more feedback in the future.