Keep on trying!
I know that you said this was a final one, but can I suggest that you make it a little better with a few hints and tips?
Things to fix:
1) When something explodes it never actually leaves the screen. It leaves that weird imprint on the screen and it really looks bad after you kill a certain amount of things.
2) I'll go with one that you already know. You obviously can't die in the game so that is something you want to learn how to fix for sure. I'm assuming it's another thing that you can just ask in the forum and learn how to do.
3) I know that nobody with the right sense of mind would travel all the way to the right side of the screen, but for some reason if one wanted to they wouldn't be able to because there is some sort of barrier there. Perhaps get rid of that if possible.
4) I hate that the background doesn't move. That's one of the things that really throws me off in flashes. If the space ship is moving then the background should slowly be moving to the left. It'll actually give the illusion that progress is being made.
Things that would make it better:
(Note, I know your a beginner, but I'm just giving you suggestions of things to slowly learn and implement into your game)
1) Make it have levels of some sort. I actually don't think that levels are very hard with this program.
2) Make it have bosses or other things to change up the pace of the gameplay. This would go along with the levels.
3) Have upgrades of some sort come into screen. Perhaps like a shield or whatnot, but you would probably just want to start off with something simple like a health upgrade.
4) Make the plasma stronger or the regular gun weaker. I found that it didn't matter what gun that I used. I suggest making the blast for the plasma a lot larger so it has the potential to hit more things.
Keep on working. I think you're going to be on your way to creating decent games pretty soon. Once you create a couple of decent games you'll be on your way to creating some good games. It's only a matter of time, patience, and practice.