Tip: At the start of the game, if the enemy ships are coming down the sides, just start over. Half your shots will miss and the ships will just sit there killing your population. Your cannons will also take massive damage which will require you to sell them and spend valuable money replacing them.
A couple of improvements should be made:
1) The arc of fire for weaponry should be 180 degrees.
2) Either lower the cost of heavy weaponry or increase the resource points for tougher enemies.
Why does every class of enemy, regardless of difficulty to kill, only give 4 resource points? If the price of more effective weaponry is increased, then the resource points for tougher enemies should be increased as well.
Give us a bonus for destroying 100% of the alien ships or lower the costs for the upgrades. Playing a level 40 times to accumulate money gets old and monotonous.
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