Use WASD or the arrow keys to move, and click to shoot. There will be more enemies added into the game in later versions. This is also my first serious scratch project with 100% of the code done by me. Version 1.1 will come out very soon! You can tell me any bugs you found in the comments and I'll try and fix! Thanks!
Version 1.1 is out! http://scratch.mit.edu/projects/554847263/