Here is my Mech Neck Walker design with an animation control menu for the Blender Game Engine.
There are three scenes.
1. Test_Ground scene: The scene where everything happens. Contains the camera control and the grouped Mech_Neck scene.
2. Mech_Neck scene: Contains my animated model for editing. I made this scene because it is a very complex object with many parts and so I wanted to have it separate from the main scene.
3. Animation_Menu scene: Overlay scene for the mouse input to change the animation and the animation speed.
Game Engine Controls:
- Left mouse button for changing the animation and the animationspeed into the menu.
- Hold right mouse button to rotate
- Mouse wheel up/down to zoom in/out
Press p-key into the 3d window to start it.
Downloads:
Some animations:

Idel 1

Idel 2

Walk Cycle

Run Cycle

Broken
Feel free to use this as a template for your own animated models :)
Here are some other versions.
Modelled, rigged and animated in Blender 2.77a for texturing I used 3d-Coat.