Sierra 7 is a tactical on-rails shooter that has its roots in Flash games of years gone by. The original was released in 2011 where it has since been played over 40 million times. Now it's been overhauled for both iOS and Android where it is available to play for free.

It's not just its previous life as a browser-game where Sierra 7 has received a few plaudits either. In May of this year, it was the winner of the Big Indie Pitch at Pocket Gamer Connects Seattle. Its distinctive, minimalist art direction and intense gunplay have earned it a lot of praise.

You play as a military operator and will handle the aiming, shooting and tactically ducking into cover, whilst moving between areas is automatic. This was done to ensure that players could focus solely on the shootout side of the game. It promises to deliver a mix of arcade and realistic action and I'm keen to see how those seemingly opposite approaches blend together.

Outside of the missions themselves, you'll be customising your load out before diving back into another series of gunfights. You'll be able to unlock 38 different guns throughout the 12-hour campaign, each having its own stats and play style. Beyond that, you'll also be able to choose different gear such as belts or vests to give your character various buffs.

That lengthy sounding campaign takes place over 13 different missions, each of which promises some replay value. You see, each time you play through one of the missions, the enemies will turn up in different places. Hopefully, this means each session will feel a little bit different compared to the last.

You can download Sierra 7 now over on the App Store and Google Play. It's a free-to-play game with IAPs.