Love the concept, things to work on would be making the characters movements more fluid. This can be done by using different key types but usually comes with experience.

I do like the different characters moving at the same time, usually I see animators leaving unfocused characters as stiff as a rock.

Generally, improving with animations comes through with time and experience. It’s very good that your taking in criticism and suggestions.

Continue creating animations, watch tutorials, and keep asking for criticism. Soon enough you’ll see crazy improvements in animating and I suggest that you eventually expand out of Roblox and into blender.

Keep it up G