Test one, there's no force, easing, anticipation. There's no sense of gravity either.
Test two, The effect particles made no sense in the fashion they scattered. All you did is tint it different colors and place it on different parts of the screen. Next time you have an effect test place the effect in or near the center where it can be watched easily and criticized better to help you further.
Test three, this is in no way a perspectives test, I refuse to recognize such a fatal attempt as one
Try this,

Black line = track/line of movement for feet
Red line = top of the head is always touching this line
Green line = horizon
Have the stickfigure, run, following the line.
I know what you mean about loosing a computer.
Keep an enclosed external hard drive for your project files back up.
The animation computer I'm building is costing me like 1,500. If I were to buy it pre-made I'd get charged something like 4,000... so I'm getting a good deal building it over buying it.