Post-Game Jam update

This is the updated version of the game, post-game jam. 

We've added a leaderboard! Now, when you lose the game, you have the option of submitting your name and score and seeing where you stand on the global leaderboard. Try your best to reach the top!

We've also fixed some issues with enemy movement, so every enemy should now be moving at the intended speed.

We also updated some UI elements to better fit the theme of the project.