I replayed it and the bugs i mentioned were fixed
It's a bit challenging to avoid zombies at the start, but once you've survived enough to get all the weapons you become unstoppable; at this point it looks fun to see bombs and blood flying everywhere, but it gets impossible to loose
I think the way the bus handles could feel better or be more fun, maybe by adding something like nitro to boost the bus when trying to go between zombies if you want to keep it simple