I played again as entrepreneur I did great at first, but the ai kept attacking and I finally won on day 73. I had to send a lot of mobsters against the last family, but all the others I could purchase them out.
Seems the ai will randomly attack, and if you simply purchase the district back they often won't counter attack. Almost as if your wanted level can go negative, or the A.I. gets penalized for attacking.
Hmmm, the other families seem more likely to attack an upgrade property, I bought a bunch of casinos in Marine Park and it was attacked, even though it was left alone for the last 5+ turns.
I tried survival I couldn't build fast enough, I had enough cash I had about 10 banks, but it takes a lot of clicking to upgrade a tower to full. Lost to about 9 mantis on wave 15 or 16.
I had about 36k when I won last level on normal difficulty, I didn't use any bonuses via research points. Most difficult part was lag. Other than lag, the most difficult levels were when I was hit with alternating air and ground waves early on, for example I only got 2 stars on lv.10 and 13.
 "A Grim Granny"){kind=icon}
 "Incremancer"){kind=icon}
 "Starlight 2"){kind=icon}
 "NYC Mafiosi"){kind=icon}
 "Obliterate Everything 3"){kind=icon}
 "World's End Chapter 3"){kind=icon}
 "Swarm Defender"){kind=icon}