mission 7; yosheeck, move the start to the upper left (sell the original solar panel), and start defending by a set of pulse lasers, I just bought pulse lasers in this. You will notice they come in clockwise, once they are at 6-9 o'clock you can expand mining to the east with no defense.
Or alternatively do not allow any 1-to-1 trading, but make a trading system with the sock exchange algorithmn, users set bits in what range they'll buy/sell. Everyday the system calculates the market value for maximum exchange, and does the exchanges.
Merlon, move your start position to the left, sell then the starting solar panel, you will notice that the enemy comes in clockwise, once you defeated them at 3 at mostly from 6 o clock, you can expand freely to the west mining what ever is there, while fighting them of coming from 9 and 12 o clock. When at 12 o clock I was finished with the task.
guide for 175.000, first make a row of traps near top, make 2 tar pits and barrel rolls with a pond at the bottom, this hard to pass, make a second one, its an near impossible pass for pirates... now make a second row at the bottom, make a barrel roll at the beginning, and then a huge loop to throw them in circles in the middle for score.
http://www.acoustics.salford.ac.uk/acoustics_info/duck/
A duck squak *DOES* echo. Generally I dont like any game that confronts one with "objective" knowledge, without any references.