I think the problem is that people don't know how to use the golden gun. First, aim the tank at about 30 degrees. The object is not high - its fast. Second, don't shoot the turtle until he's about to stop. He'll fly forward like he was shot out the cannon. Its about forward momentum not height. Just do that (the chest bomb can be helpful too), and you can beat 3 mil easy.
I really would love to have some information about the best gem combinations. I've looked around and really can't find it. For example, does the mana gem (orange) gain on the multi-hit gem (lime) each time it makes a hit, or only on the first hit? What about splash (red). I feel these kinds of pieces of information can really help in playing. I'm not trying to short cut the game - and I don't use hacks - I just want to understand the rules so I can optimize my strategy. Thanks.
One last thing- a 30 angle give you some lift, but more importantly, forward momentum. When you are 3 cans of thrust, you should be aiming for 30 degrees or so. Even flat might work, since you are using the thrust to get you higher.
Well - in terms of angle, anything higher than 45 degrees is a waste of energy. You max at 45 when you are unpowered. The best advice I found was to buy as many thrust as you can and use them ALL right after take off. You'l be aloft for quite some distance. Beyond that, fill in in order of expense - skis, freaky...