HOW TO IMPROVE WALK ANIMATION?

The legs look ok, the color indicates one leg moving in front of the other. Although it's very subtle. I think the problem is the feet. They are stationary, only shrinking by 1 pixel and there is never space in between. It kind of looks like he's shuffling his feet to build up a static shock. Make the feet move further apart, which probably means having the legs move further out too, and see how that looks.

Also, be sure to test how it looks in game. It might look weird like that, but in the game moving around a map not so much.

Something about the way his feet move seems off, like it's only half the animation. I would say just try a few different variations, like one where his feet don't leave the ground but have space between the feet, and use your best judgement on what looks right. Don't rely on other people to say if something should be in your game, that is up to you. We can give tips on how to improve the graphics, but I would never tell you if you should put it in your game or not.

Btw, the sprite looks really cool. I would recommend you examine how other sprites have their feet in walking animations. You could even record yourself walking, and move it frame by frame, and pick key frames to base your sprites legs on.