so far so good...you should make the playing screen a little bigger or the sprites smaller. It's good so far. Are there upgrades? Most shooters that people put out don't hold my attention too long because they aren't polished. This one is good so far. Keep working on it.
It's a form of flattery. Nothing wrong with making a similarly themed game. Like saying Stacker and Perfect Balance are copies or all the millions of zombie games that are very similar.
It charges you twice? once when you select the unit and another time when you place the unit. Also you need something around the active unit so you know which one is selected. Otherwise good game.
I was just about to comment when I saw that other comment about being dizzy. I can't play anymore cuz I'm nauseaus(sp?) anyways fun game in short spurts for me.