Thanks for playing and the feedback! The coins were only intended to act as a pirety health system by the original design, but giving them more purpose (and consequently more value to preserve) would be an awesome way to extend the system.
The input problem on attacking and bouncing on slopes would definitely be first priority in further dev and you're absolutely right there, but for the sake of having a "less broken" product for turn in we decided to punt on those for other priorities.
Thanks again for playing!