It's not bad, it's just not good enough.
Objects floating off walls, skirting boards misaligned, the garage door is too small for it's own frame, the kind of polish issues that break immersion the moment you spawn in. Some cars have floating lights because parts of the body hasn't loaded in or hasn't been set up correctly. There's an upgrade system you can access to get upgrades for your car which doesn't seem to exist, it says "go to the office PC" but I've looked around the starting area 3 times and there isn't one, which leaves me to think I need to grind around 20 runs to get a new car and hope there's another area past this one with the PC in it, but that's just speculation. Showing cars you don't own and can't access yet makes no sense.
The UI looks like it was made with Claude. It's out of place, generic, and indistinguishable from half the other games on s&box.
The core gameplay loop is holding W. That would be okay... if it felt good. It doesn't. Zombies Jolt you car on impact in a way that feels broken rather than satisfying, which somehow makes the simplest possible game loop feel bad.
I was also going to say "not a bad concept" but someone else's review pointed out that this is just an Earn to Die clone. So it's a stolen concept executed poorly. s&box is dying and it needs developers willing to actually raise the bar, this doesn't however.