Gonzo Mad Max/Tank Girl vs. literally the people ruining our planet and culture is a great theme for Havoc; the satire is cutting, and you do an excellent job selling your setting. The character concepts are unique and feel mechanically distinct and unified (awesome art as well!) Each character having a unique motivation or "quest" is cool, and I wonder if there could be some mechanical rewards attached to completing those quests. I like the ability to use Power specifically to give bonuses to other PCs; that's way more interesting than being able to use it to give dice to yourself. I also like the ability of Ground Control to spread injuries around the team; it gives a good tool for managing dramatic tension and avoiding the feelbad where a PC dies purely due to a botched roll. Your mission structure adds some clarity and narrative direction to the very freeform system used in EtR while keeping that flexibility. I notice that a few of your secondary objectives seem to be for narrative purpose only, and I wonder if "helping the planet" is enough of a payoff to incentivize completing them or if some kind of mechanical advantage could be added to those as well. Perhaps the campaign could benefit from a capstone objective for the PCs to escape the crashing city alive, though there's no problem with just taking that as read.
My partner's headcanon is that Sineater is from Uranium City (that's a real place in Saskatchewan, and no, it is not nearly as cool as it sounds)