Bloons Tower Defense 5 - Daily Challenge May 16, 2013 (Behind You!)(NAPSFRILLS)

Behind You! - Park Path rounds 40-70. 4/2 Boomerang Throwers, Ninjas, 4/2 Bomb Towers, Ice Towers, Aces and 2/4 Apprentices. 5 towers max. By aperson22

Video is on 3-5x speed
No Agent, Premium and Speciality
(Please comment if you have better strategy)
For more walkthrough: http://bloons-tower-defense-5.blogspot.com