OOP and the Zombie Arena project

The initial problem we are facing is the complexity of the current project. Let’s consider that there is just a single zombie; here is what we need to make it function in the game:

• Its horizontal and vertical position
• Its size
• The direction it is facing
• A different texture for each zombie type
• A sprite
• A different speed for each zombie type
• A different health for each zombie type
• Keeping track of the type of each zombie
• Collision detection data
• Its intelligence (to chase the player), which is slightly different for each type of zombie
• An indication of whether the zombie is alive or dead

This perhaps suggests a dozen variables for just one zombie, and entire arrays of each of these variables will be required for managing a zombie horde. But what about all the bullets from the machine gun, the pick-ups, and the different level-ups? The code from the much simpler Timber...