It would be better if you used the "nearest neighbor" interpolation to keep the integrity of your pixel arts, so the sprites don't look that blurry when you resize them, kind of like what you did with on the thumbnail. The platforms also have some "holes", where I was falling into all the time. The intro is very funny and I like how the game style suddenly changes. You could also take a look at some tutorials on animating walk cycles. This one is very good: