Atari sure now how to hold on to an idea. Outlaw has been kicking around since 1976 and while the original was more of a reaction tester, the iOS update has kept things simple by returning to the classic gallery shooter genre.

Enemies slide on in to position, either from the side or from behind some cover, and slowly take aim before firing volleys of shots at you until you either keel over or shoot them down. As fast as your six-shooter may be you'll need to move up to higher caliber weaponry to stay ahead of the curve, with enemies gaining faster reflexes and absorbing more punishment as you get closer to finishing an area.

Thankfully the game is quite forgiving - well, only if you have a keen eye and fast reflexes. Quickly dispatching enemies can activate temporary boosts such as increasing your armor or slowing down the firing rate of enemies, but best of all the level will spawn power-ups to shoot. These are tied almost exclusively to how well you're doing on the stage; if you're finding yourself overwhelmed an explosive barrel will help to soften them all up; if you're near death a health pack might give you the edge to win.

Strangely this kind of intelligent power-up system gives the game far more flow than similar outings, especially as it manages to fill the gap of gameplay where you're waiting for enough cash to purchase an upgrade (be it a new weapon or an addon for one you already have). The difficulty curve is further adjusted by unlocking new stages while you're still in the middle of other areas; these will invariably have a lower starting difficulty, meaning you can jump back and forth as you earn the cash to work your way out of things.

Unfortunately there's no getting around the fact that it's a fairly standard shooter with a control system that can be fiddly at times (virtual sticks and precision aiming still aren't seeing eye-to-eye). Static enemies slide in to predetermined slots, making the whole experience feel repetitive if you're not patient enough to wait for a new weapon.

Outlaw does its best to remain true to the 1976 original while still having modern sensibilities, but the end result is an average game with the appeal of 90s retro classic.