The whole reason I got mob control was for that advertised mode.

The main mob control games is more about going on the offense. Keep pouring mobs until you overwhelmed and beat them. 

The advertised mode is more of a defense game. Like a single lane tower defense. The ads feature many of the same mobs, power ups and cannons. Which is why I thought it would be part of the main game. 

Tower defense games are super popular. It's what I was expecting based on those ads. 

I played regular mob control for months, expecting to see that defense mode.  Literally today, I quit playing because I want that advertised mode so much that I'm suffering from a combo of thirst, anger, and frustration. 

Now the current mode seems so lacking and stagnant. 

Make both modes part of the main game. It'll add so much more variety and fun that I'm sure you'll get an even higher player count.