Inner curses

Made for #255 Trijam with the theme Darkness Within.

Updates added after Trijam:

• Tutorial (it's just a text tutorial, but at least it's now in the game).
• Added a few other enemies apart from the basic ghost.
• The camera now follows the player.
• Additional effects have been added to curses, and their negative effects increase over time.

During the game jam, I ran out of time, so I didn't have the opportunity to balance the game. I have attempted to make the game more balanced in this update, but I'm not skilled at balancing, so it may still be an issue.

Controls:

• Use WSAD to move and the left mouse button to shoot.
• To activate and deactivate each curse, you need to click the key associated with the respective number.