First off the catapult is you best tower. I pretty much only had them, well and a couple snowball towers. Build a basic maze with catapults and then fully upgrade them.

Now for the cheating part.
Right after they fire, hit the pause button. The mobs will freeze, but your towers will continue to reset to get ready for another shot, and once they do, unpause, let them fire, and then pause again and repeat this step until the mobs are dead.
Doing this will let you destroy any mobs before they really get a chance to move, thus simplifying the game even more than it already is.

would prefer tips on how to get 200k points in that game i only got 105 on hardest dif and no life loss :S

Thats called cheating and will get you frozen most likely.

yeah, there is a good chance of you getting frozen or at least suspended for this

not to mention its not a hard game to begin with, lol