Diesel Valkyrie

I don't get it where the creators take the ideas for so many zombie games. This time the content is as always, you are a soldier and you to clean Europe of the zombies. You are alone and soon enough you are under pressure thanks the thousand of zombies. The weapon you have is gun only but you can take temporary upgrades. Better guns, or some special modes last only few seconds so plan well. After finishing one level you continue into the next one. But it's always about the same, killing zombies.