You need to bend the knee a bit and the foot. As is looks like he's just dragging his feet around.
Also your bounce I can't quite get it, but seems bouncy to me, not smooth accompanying the walking.
Hmm, yes, but how to do it in this view? The only thing I can think of is using darker color for the bent leg to show it.
About the bounce: where exactly do you mean - the side loop, right? I can see it now.
Sure, reference pictures may tell you that your picture is accurate, but if it doesn't look right, you should fix it anyway. After all, when it comes down to animation, most actions have to look exaggerated.
Good luck with your game. Isometric is an incredibly difficult choice.
That's a good point! And one I tend to forget all the time.

I really wanted to make the animation as civil as possible! Because in many games, the animation is right and still somehow off because of exaggeration, like runnig in Shadowrun or this famous walk cycle reference:

That's just something I don't want to end up with. I have to find a middle way, I guess.
Thank you for both of your comments and also for your encouragement, Danvazare. It's not easy, but I always wanted to make one.

Ok, I'll try to fix the down loop. What do you think about the side and isometric loop - is it okay, or should I make him raise the foot higher, too?