bony, jointed, stalk-like appendages, resembling the legs of some monstrous insect, that slipped and slid across the smooth stone floor like a newborn calf trying to stand
You use a lot of passive "ing" verbs in your action scene(s). These can be good for setting a scene or description, but with action action it's usually better to use the active version. For example here:
"Run! NOW!" TJ shouted and yanked at Alison's sleeve. Her eyes focused on the ground where their friend lay. He twitched slightly.
You don't need to remove them all, but the more you can change, the better and faster the story will flow.
