It's am urban-dead knockoff with added vampires (that the creators have a fetish/bias for playing as) and a 'donate'-to-win mechanic.

The only other difference to note is a bigger emphasis on combat (that the developers claim is "streamlined") which means more damage/less health and a 2:1 ration of weapons vs every other usable item. The weapons are also grossly unbalanced which makes 90% of them redundant as you work your way up the tiers towards the cookie cutters.

Stick to UrbanDead unless you have a vampire fetish (or go and read twilight).