At first, confusing as h*ll. Started poking around, found some instructions under "intel" on the opening game screen. Also, there's a Wiki with all kinds of details (see the, ahem, Kong "instructions" tab). I guess medics heal if you stand close enough. Also, I think having 6+ men on the field causes the Germans to bring out all the really horrible stuff. Like the dark sense of humor. I think this game will grow on me.
I'm not sure whether the developer will see this so many years after the release, but here goes. You have the potential for a fun game. You have some of the basic mechanics worked out, but it is going to take a lot more work. Consider background designs, color. Add something to make the square grow again, but also include something to make a round finite. A time limit would be functional, but boring. Maybe a picture assembles in the background, and by the time it's done, so is the round? I don't know, something creative like that. Also, adjust the speed, number of balls, etc. Having the different colors, including the gray dots is good. If you still work on games, good luck!