i can finish first 2 rounds easy, but in round 3 i cant kill monsters they eat my hp and in round 4 im dead... I try random towers, but best combo for now is 1 knife tower back, and 1 magic tower in front, after that add 1 more knife tower mid and upgrade knife tower back... Magic tower on front can kill green magic units, but problem is too many portals on mid, so monsters from right side steal my hp...