Not bad, not bad at all!
Typically, you don't get the instructions on how to remove the "white" borders on imported pics in tutorials. That was a nice inclusion. Also, I didn't find out about onion skinning until only recently, so that was an excellent point to bring to light.
With Mario's animation, though, I think he needs a little bob in the 2nd frame (Hat cannot match frame previous), otherwise it looks like he's just kicking his legs and sliding when you tween him across the stage. I mean, when you think about it, it'd probably be really hard to keep your head completely level while running. A few small pixel adjustments up on that second frame will make the animation look more natural. Also, copying and pasting that second frame after the third one looks a lot better than looping to the first one again.
I hope my review was constructive and useful. Nicely done tutorial!
You have a few good points there. I normally make a motion tween that smalls him up (the running mario) a bit, making it really look like he runs. Actually making it lower in the beginning might not be a bad idea xD. And it depends per Sheet...I guess mario could look a little more smooth using the second frame twice, but it would have made it harder to explain :P
Thanks for your review
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