This game needs 2 or 3 things more, like: a customisable character. Random equipable loots (i 'm lvl 7 at this comment moment and it seems like it doesn't exist) because most of mmorpg have that kind of things, that helps saving some money for a higher equipement later in the game, but that would mean that we would be able to choose what we can equip/buy, and that would probably be too much for a game that only ask to be launched. Random unique monsters that could loot some unique items.
Anyway, that game is fun and i like it.
There should be a way to save our zombie specimen from obvious death, i mean what kind of scientist would say himself:" Hey i spent 8 month researching on my favorite specimen, let's see what happen if i use a shotgun on his head."
There also should random events with the use of items, why not a bunny killing your favorite zombie, or your zombie accidentally killing himself with the kebab stick. Who also should be able to shoot at our zombie by ourself, that's more funny.