I'd be surprised if anyone plays this but I am aware of several known issues:
Settings --> Resolution and Full Screen.
In Game --> Tower Health updates based on current health.
In Game --> Retry Button is not trying.
Enemies scale extremely slow.
Range is supposed to cap at 20.0 but it can go until 20.5.
I am waiting for Brickhack 11 to conclude before I get to fixing any of these issues.