Covid Blaster (jomarch22)

Modified 2D Shooter Game: Covid Blaster

- Changed overall theme from space shooter to urban shooter to beat COVID

- Made new game sprites (player and enemy) & sourced other art for game from free, online sources

- Changed behaviors to allow:

1. Random firing from multiple guns (COVID boss in second level)

2. Enable scrolling

3. Allow enemies (level 2) to be vaccinated (by player) or infected (by COVID)