Then some personal opinion, in the first flight level boar enemy may always hide behind the cover, then when you are close to suddenly shoot or drop attack so very annoying, hopefully it can make the enemy do not hide all the time.
Regarding the missiles, I hope to be able to adjust a little, the second flight off the appearance of missiles on the upper position leads to often can not hit, and the role of moving relative to the missile speed is a little too slow leads to very difficult to pull away from the distance or to take the test to move to avoid. Here's a tip, for tracking bullets, you can set a slightly slower horizontal launch at first to give the player time to react, and then start tracking at normal speed, as well as rotating a little slower to help reduce the difficulty.