Unfortunately, it suffers from a ton of major issues: game mechanics, battery drain, no storyline, and so on. Though the game is free, you're prompted to purchase upgrades and health packs after each mission, and if that's not enough, you're also constantly prompted to turn on notifications so the game can spam you with updates.

Six-Guns may be free, but this is definitely a case of getting what you pay for.

This app was tested using a Samsung Galaxy Nexus running Android 4.0.2