A few things
Well, I'm not that good at these kinds of strategy games in usual, so if this seems slightly harsh, please excuse me. I do like playing them though =/
First of all, when you send soldiers from one star to another, you have to send all of them. This leaves the star you just send soldiers from; partially open for attack. I understand the point of having other stars feed your main star, but this does not help if the enemy attacks directly after you send your soldiers away, especially with soldiers leaving automatically upon reaching about ten.
So, it would be good if you could send a certain number of soldiers over.
Also, it would be helpful if, there could be rewards or power ups, otainable over the course of the game. I know in most games like this there isnt, but it may help^.^
Just use your imagination
The gameplay was alright, except for that first problem.
A storyline might help, but is not necessary in this kind of game.
6/10, 4/5