I got 3m doing this : buy 50 nukes , shoot with golden gun , use missile , use nukes until you have 0 and tadah ! you'll probably reach 3mill like me =D
This might work:
Get 100 Nuclear bombs , get a tank , get a golden gun , get a missile , fire your turtle , use all bombs until you have 0 , shoot your turte with all the ammo , use missile , you may reach more than 2.5mill if you dont hit spikes and if you're lucky and get more golden gun ammo you'll get 3mill. :)
 "Rotatix"){kind=icon}
 "Red Remover"){kind=icon}
 "Cover Orange"){kind=icon}
 "Pizza King"){kind=icon}
 "Bloons Tower Defense 3"){kind=icon}
 "Free Rider 2"){kind=icon}
 "Toss the Turtle"){kind=icon}
 "Create your own TD 2"){kind=icon}