(GIF preview)

I made a template 4-frame walk animation as a guide to animate more complex characters. It is not the most natural way of animating a walk, but quite useful, considering the low number of frames.

If you are working with low resources you may find it useful to do your characters walk in 4-frames. (2 frames are shown twice)

Walk frame sequence: 1,2,3,4,3,2

You can use it as it is in your games, if you like.