What happened to this game – Age of Zombies® Review

I use to play this game on my psp and it was really fun.now only the stupid sentrys spawn in the survival mode. i miss the times when the biggest thing I had to worry about was giant cyborg zombies.what happened to explosive zombies in survival and weapons spawning everywhere randomly.why is the original future survival map gone.it was my favorite map
Review by tumblleweed on Age of Zombies®.