you should fix the walking, i know it's scratch but you should look up a tutorial on smoother walking, the position of the gun is really awkward, you can spam spacebar and the gun will just shoot a straight line of projectiles, you can press r mid game and it bugs out, you can't walk and shoot at the same time
you should add some more stuff to the game like powerups and enemies that shoot something or do something else, it would be nice if there was a score and highscore system and some sound effects