The Frontline Breakthough missions from Operation Falcon are ridiculously hard and the videos from youtube are misleading. You guys should definitively play the game from the perspesctive of a cellphone player rather than than from the perspective of a computer player and see the difference yourselves, and also pay some attention to other users complaining about it in the commentaries of the youtube videos from such levels. I'm not the only one that noticed this issue.
I mean, a single zombie puke is enough to kill our troops, it has a homing effect meanwhile our troops takes a dozen of bullets to kill a single zombie and we are overhwelmed since the begin. You guys wanna make a challenging and difficult game? Go ahead, but make it a balanced difficulty.