Been playing The Last Stand: Dead Zone since a few months after it was released. The game ran great when it wasn't as popular, or "opulated". Ever since that time,(several months after it was released) the game lags like HELL!. In the past few years since it's release, I have purchased a top of the line gaming PC, upgraded my internet connection/speed. Your game...still lags like HELL! Nothing at my end to cause the issue. Stop being cheap *******s, and spend some coin to upgrade your servers, or at least give The last Stand: Dead Zone, some more bandwidth at your end! I have talked to players who say that don't lag at all. Maybe they live close to where your servers are located at. Regardless, I know it won't change, and in the end, I will stop playing.
The servers are hosted by ConArtist Games as this is an MMO game. Have you had a chance to check out some of the common causes and solutions and contribute to the information gathering that the game makers are looking for? The link will take you directly to the ConArtist Games forums where you will be communicating with them directly.