Even at later levels, the game lacks staying power because of how the timing goes. Return times are simply TOO long. Please enable us to upgrade the Deathmobile to reduce return times by a percentage.
The most broken build I've found is 3 Dogs with upgrades, 1, 5, 11, 15, and 7. Face Lick can target the user which, when spammed, is a whopping +180 HP per three uses to your team's health. They can also, when next to each other, heal 10 HP per turn, giving a net gain of 30 HP per turn when not taking damage, and every kill gives an additional 30 to current and max HP. They get global buffs from other allied dogs and can just wreck everything.
 "The Last Stand: Dead Zone"){kind=icon}
 "Terminal Love"){kind=icon}
 "Deadly Neighbors 2"){kind=icon}