Gun Bros
If you have an affinity for shooter games where you get to be the hero, shoot tons of bad guys and eventually save the day, Gun Bros is for you. The storyline isn't much, in fact, it's as predictable as can be. You're simply a gun toting special soldier who is bent on carrying your mission: "to protect the cosmos from the Tyrannical Oppressors of Life known as T.O.O.L."
Armed with tons and tons of guns, you have to defend yourself against waves of enemies. They start off quite easy to kill but as you progress, you'll encounter bigger bad guys that'll test your skills. The game is offered absolutely free and plays on your iOs and Android devices beautifully.