Smash Hit is actually one of my favorite Android games. This title is on our list for best casual game, best offline Android game, and now best free games, because it's that good.
Smash Hit is hard to explain, but it's basically an endless moving first-person game where you throw balls at glass windows and other objects as you move ahead. It sounds odd, but it's extremely fun and addicting. The game has millions of players and nearly 4 million reviews on the Google Play Store. In fact, you can also try PinOut from the same company.
With this game you don't have to spend any money, there aren't any ads, but you can donate to the developer if you'd like. Paying for the PRO version doesn't do anything, you're just supporting the developer. As a result, we're calling this one of the best truly 100% free Android games.