I'd heard some complaints about Sentry satellites, people don't seem to like that you can place one down only to have a random meteor immediately come along to destroy it. Do combat that I've modified Sentry satellites to attack anything that is going to collide with it first and then focus on any other close satellites.
I've also been concerned about the difficulty so I just made one slight change on that end and increased the speed of small meteorites. That's just a start, hopefully I'll have more in that vein coming up.
I also added satellite descriptions to the instructions. There are functions of the satellites that are not immediately apparent so they needed to be described somewhere.
Sentry satellites will always target the nearest enemy with enemies that will collide with them taking precedence
Slight increase to small meteorite speed
Added a short description of each satellite in the game instructions