[iOS/iPadOS] [Early 2010s] Zombie tower defense game using turrets

Platform(s): iOS/iPadOS - I vividly remember playing this game on an iPad like one of the first ones.

Genre: Tower Defense (Zombies?) - the zombies part I’m not sure but I have high confidence I remember the enemies being zombies

Estimated year of release: Early 2010s

Graphics/art style: Top down, somewhat cartoony - I remember colorful ambient lighting like green emanating below one of the turrets and maybe a purple light from one of the maps?

Notable characters: I remember it was this bulky dude with brown hair and white shirt or something like that - I have low confidence I remember this correctly

Notable gameplay mechanics: From what I remember, you go around placing turrets around the map. I can’t remember if you have a character that actually moves around or you drag the turrets. I remember one turret so vividly it was an MG turret with 3 legs almost like a bipod with a green light.

Other details: for some reason I remember the turrets possibly had a cool down/overheating period? Not sure about this