Mate females and males and try to reach maximum population - but beware of black death!

Author Comments:

Just a small time-killer game where your job is to maintain life! Mate females (red balls) and males (blue balls) and try to reach maximum population - but beware of black death which strikes occasionally...
Use mouse to place an "isolation circle" on the screen. Red balls and blue balls will reproduce inside isolation circle. Try to maximize the number of balls. Isolate black balls in their own circles to eliminate disease. Try to maintain life as long as possible - all life will end eventually.
Left mouse button = drop an isolation circle. Space = clear all isolation circles (except when black death is around). P = pause