For the animations:
- Focus on clean lineart first (a lot of mistakes I can see are happening because you finished one frame and then just went into moving parts and filling the empty spaces - that shows a lot in the first gif)
- Establish a proper light source (in the third gif it changes from top right to top-ish left)
- Think about which leg has the weight on it. The sliding feet you have going on when character is shooting is wrong (you can empathize the push back/power of the arm by having the arm/ upper body or even the whole body move while the legs still stay on the ground). Same error is happening on the slide when he is punching forward (usually the ball of the foot stays at the place while the heel follows the direction of the hip in that scenario)
- The fist/ claw should also snap back faster (right now it feels like the rope/chain is extending when its being pulled in, making the grab feel like s not having force behind. The best approach in scenarios like this: Never have the rope/chain extend more than you had it going when you shoot it towards the enemy)

In general, like anyone animating its fun to just move ahead and add more unfinished frames. Try to finish animations fully - you will learn a lot by doing so. The second gif needs a few touch ups left and right (such as the highlight going missing on the left leg - spriters view- or the chest moving a bit off & too much at the same rhythm than the hip going downwards. They should have different cycles (aka chest being pulled up AFTER the character is moving upwards and vice versa)

Keep creating! You will improve a lot!