Release v0.2

I added a rocket launcher, and I think I thought of a name: Pico Party. Jack C suggested it, and I thought it was a great name. I think compared to last release, I added health, pause, volume settings, explosions, and maybe some other things. You can actually pause the game at any time, so you can get a pause menu overlapped with the title. That will obviously be fixed soon, but I just wanted to write this out now. I added a little animation to the hearts when you take damage, and I'm not really sure how good it looks. I think it works, but I'm definitely going to add something to it in the future. I also need a rocket shoot sound, which is not just the pistol shoot sound.