I played the game about 6 times and got up to a score of 23.
Your game has also inspired my son to see what he can do! I have a couple of Gamemaker Studio Professional licenses, and he want to see what your game would look like using that tool as compared to Scratch. So he's going to attempt to duplicate your game idea. (I'll post the results here if you'd like to see it.)
he also had a couple of suggestions to pass along, which you may have already thought of . . . First off, multiple lives. He found that frustrating that one kill and the game's over. Second was the ability to have two or three shots on the screen at one time (he'd keep getting killed while waiting to be able to fire the next shot). And lastly, some way to "dodge" the enemy. If there are three bad guys on the screen at one time, you're dead. No way to avoid it because you can't shoot fast enough to shoot three of them, and no way to get away from the one you miss. (Well, I guess you could speed up the bullet, or make the bullet go away when it hits a bad guy so you can shoot again quicker.)
