Making instances of objects with Arduino

While programming a space invaders game on the DIY Gamer, I ran into some restrictions. I had to make arrays of variables for each enemy, bullet, and player in the game. Can I just program each as an object: enemy, bullet, player and just manipulate the instances of each object in game? Instead of global variables could each objects have their own instance of a variable?

Can someone please help me optimize my code so its not as complicated.

DIY_Gamer_space_mauradersV1.8.ino (11.9 KB)