Wow, great feedback! Thanks a lot :)
The idea with the pausing was so that you could take a look at your situation and be able to read the descriptions of a tower you chose (scrolling works when paused). It didn't occur to me that being able to select towers while paused is a much better idea than clicking on a tower and then pausing the game.
To address the battery, yes we did have the idea to upgrade both the towers and batteries but ran out of time, unfortunately. We'll be working more on the game after the jam to implement all these things!
I really like your feedback, very insightful, thanks for playing our game :)