I found the trick is to lure the zombies away from the bike get down to 1 zombie collect gas cans then kill zombies. IT does need to be blanced more took me a hile to find a good plan.
there no chainsaw from what I can see yet a medal for it?

your bike gets overwhelmed too quickly because your gun is so underpowered that its impossible to fend off the approaching zombies

Upgrades arre expensive, zombies are OP, your bike sucks, your pistol sucks. Well, this is one of that games that you could enjoy a lot more if it was balanced.

For a good game, simple mechanics are the best. Don't try to come up with clever ideas, only for the majority of your players not understand it. For example, I assuming that i buy upgrades, but have no idea how to do it. This is why you get a lot of negative scores, because you made it confusing, and frustrated your players. All you have to do is any open shop, buy weapon. Simple. But instead, people wander around for a long time killing relentless enemies with an under powered gun, wondering, is there more to it than this? Need to think this type of stuff through before you implement it.

Make a graphics quality option there is too much lag.