It could have had a sequel with more potential like more upgrades and guns possibly even stationary guns or some stuff like that
and btw. zombies seems to be cheating:D you can get upgrades up to 10 but when I had about 15K kills and randomly clicked on one of them he had about 20 of every upgrade :D
awsome game the easiest way is to throw fragment nade into their lines I love to do that >:D coz it will blast half of em away:D
R.I.P. to everybody who died by my hand (R.I.P.=rest in pieces >:D)
 "Luncheon Of The Dead"){kind=icon}
 "Endless War 3"){kind=icon}