I like the game its well made but i wish the end was more then just a "you won". Maybe make it so we can see the aliens and have it to where the communication between you and the lieutenant is more stressed depending on the situation. Also the ships need to fire at you from a greater distance, this ridiculous short range weapon that you gave them seems ineffectual. Maybe make a hard mode so that those who aren't new to these kind of games can have a much more satisfying challenge. And add a shield to help with the laser increase that way you can have a better reason as to why the lasers they shoot are so weak.
Another thing, can you please work on the grammar. I know your from Asia and communication there is different, but you have done surprisingly well (better then most Americans). Still, you need some one to help you with sentence structure, I'm sure you can have someone help you with this.
I also agree with s4nji, add new grounds medals.