Though the game is
extremely buggy, it is making good progress. Heres some things I believe you should begin working on.
~~ 1: Fix the Bugs ~~
A: Sprite Bugs: You need to fix those sprites in your program, leaving them there and not dealing with them until later will just make things harder
- Bugs I found include many sprites not existing when the player or enemy blows up. Track these down and fix them.
A: Collision Bugs: I noticed while playing that a lot of times the collision with the enemy and the player didn't work.
~~ 2: Gameplay ~~
A: Enemy AI: Try to set the AI so that they attack back. Also try to set up new AI movements so you don't feel like your playing a never ending loop of the same alien.
B: Appearance: Add some more effects, like the laser changes color as it moves for example. Also try to add some different looking enemies into the game, possibly that do different things. I personally like a game that has a lot of different levels, it gives a more arcade game feeling. Try making levels with different backgrounds, maybe your flying over mars in one of the levels.
C: Ideas/Thoughts: You could possibly add power ups that boost your weapon up. Maybe have special weapons that track down the target or destroy all the enemies on the screen. Get creative
I can see this game being a fun game. It has a good idea behind it, and is working towards a cool 2d game. Keep working on it and If you can, update me on your progress in this thread. If you need any help coding when you are stuck, I will try to help you (I'm Not to good at 2d though) Good Luck