How to win in a few easy steps: You get money for every level even if you don't finish it, and rewards go up nicely as you progress. So grind on the highest level you can reasonably get to until you can upgrade to the homing missle (10,050). Then get to the next highest level you can get to and upgrade to the best ship (64,590). Now you can only reasonably be defeated by the final boss. For this guy start to the far upper left or right to take out the right or left gun. Shift to the other side, take out that gun, then concentrate on the middle. DONE and DONE.
That's it - finally finished with this game. When I work for 1/2 hour to complete a special tile and WIN only to have it crash and not register the win there is no reason to keep playing.
unless you play A LOT I find the contested territory a bit pointless. I'm typically up against players with higher levels than me, and even if I do win, the game resets before I have a chance to collect my money and I'm left with nothing for having gone through it.
so... basically it takes me weeks to build up the resources to play the same game that I could play in a single sitting of Bloons Defense 5. I do believe I'm out.