Looking good,
Mastermind . Reminiscent of Origin's classic,
Autoduel. There was something mystical in that game about cruising down the highway, suddenly getting into a frantic battle with another car, and ending it by ramming into its side and thoroughly machine gunning its occupant. Your game has the advantage of entering a building and slaughtering the people sheltering there.... loving it.
Two thoughts...
a) What was great about Autoduel (and Mechwarrior) was Salvage. And that Salvage was based on a mechanic skill. And that you points put into Mechanic skill were points that didn't go into driving skills, gunnery etc. The difficult choice is always a winner. A decent driver, who is always broke. Or the wiz mechanic, who can strip a car of parts, but who sucks in fights. The fun is in starting with a real piece of shit car (or mech) and working up to a death machine draped in the bloody scalps of the defeated.
b) In large numbers hit point bars suck. And they don't seem to serve much point here as the deaths are over in seconds anyway. Instead of starting with full green bars, what about starting with no visible bar, and filling it with an expanding red bar as they are damaged. Or (preferably) lose the bar... and just increase blood splatter the nearer they are to death. It's nice to have a trail of blood to follow as you leave the building, like breadcrumbs (except in this case chunks of flesh and brain matter).
I would pay for a budget Autoduel style game, with fog-of-war building raids, brutal Hotline Miami combat, a fucked up post-disaster setting (even something simple as widespread food/gas shortages that cause riots, the loss of government and law and order... I mean, one flood and Hurrican Katrina turned New Orleans into a lawless looter's paradise), also food scavenging, a low petrol gauge, one flat tyre. No monsters, no mutants, just a desperate homeschooled population and too many firearms. No laser mini-guns, no force shields, just a molotov cocktail in one hand, a sawn-off shotgun in the other and an easy "Fuck you!" on my lips for my fellow countryman.
For combat, personally I'd aim for a nice quiet pacing, with lonely deserted roads, empty buildings, winding your way carefully through a cluster of stripped and burnt out cars, followed by suddenly encountering a gang of motorbikes, or an overpowered truck T-bones you through the intersection, or your player creeping through a torch lit building when a machete gang bursts out of trapdoors and closets sporting confronting hairstyles. Don't get people too attached to their cars, Grand Theft Auto had the right idea. You should be able to dump your beloved pick-up, limp across a field as a sniper takes shots at you from the road, and grab a a beat up Volkswagen (and hotwiring it if you have at least one point in Mechanic skill). If you have a loaded shotgun pointed out the driver's side window then you should be still in the game.
Make good use of the quiet moments... like finding a fresh corpse to poke through his backpack or a defenceless couple, cowering in the corner of their home. Do you ignore them as you empty out their food locker, staring ahead with your dead eyes oblivious to their pleas to leave something behind, or do you waste a valuable bullet on the male. (Add a 5% chance one of the figures attacks with savage fury of a cornered animal as you approach, or fires a hidden handgun, or whistles, springing the machete ambush you walked into.)
That would be my ideal game, but obviously a lot of work. And yeah, if you think you'll get a million dollars for mindless clickfest, instant health regeneration, and cutesy zombie ninjas... then betray your beliefs and create that. But if you Kickstart the Autoduel option put me down for a box copy no matter how rough are the sprites and sounds. It's all about having a well realised strong concept you can communicate with others.