As I stated before, drawing polygons takes up a large amount of time in each game engine cycle. The less polygons that the computer needs to draw, the better. This is the Mech that I designed for the game:
If the game were to draw every single polygon of this model, it would be incredibly slow. The next best thing is to make it a 2D sprite.
2D sprites generally kill a game, but in 90% of all games, they are not used to their full potential.
I figured out a way of keeping the mech a 2D sprite, but making it appear 3D:

I took 36 pictures of the mech at different degrees of rotation:
Then I created a rectangle that would always face the player in the game. Based upon the difference in degrees between the player and the mech, the frame would be changed to make the mech seem 3D. (See 3D 2D sprite calculations)