Diverse enemies

[BenLeadbetter]

Enemies can take on different forms and have different behaviours. This would serve as a proof-of-concept for adding further enemy types going forward.

Success Criteria

• The single enemy type is replaced with three different enemy types.
• The different enemy types should appear different (different sprites)
• The different enemy types should move differently.
• The different enemy types should introduce different threats to the player.