Global Defense System

Surely the countries would give more funding to protect Earth against a threat like that, right?

Ok, I've played this over and over and over, following all the recommendations listed here, and I still can't even get past level 7. The difficulty is too random, and the penalty for even a single mistake is far too high on such early levels. For example, as soon as I clicked to begin level 6, four asteroids were already on-screen (three of them were the larger of the two varieties available at this stage), barreling towards Earth. I had three sledge guns, but I didn't have time to even slow down all of the asteroids. *ONE* of them made it through, and did 37% damage. The next cluster that spawned was similar in makeup, and *ONE* more made it through, doing another 30% damage. In just two hits, I was down to 1/3 health. That is excessive.

Why isn't the world turning to Madagascar to help?! They can survive anything

Very good concept for the game, overall; it just needs a few difficulty tweaks like less health for the asteroids, or there could be better visibility at the start or no limit to begin with, another would be more money to compensate for the massive damage the asteroids cause, which is another consideration. again, good game, but the execution could have been better.

Stay at 3x sledge until you get two auto turrets ~lvl 8 with at least 2x range upgrade, then get one red laser cannon in the center, two blue on the outside, replace red cannon with antimatter bomb, and you should have no problems.