Poor Greedo. Just as things were getting interesting, Han Solo shot him in the gut and killed him. His time was brief yet entertaining, and the same is true of Star Wars: The Force Unleashed on iPhone. The game fires off an energetic adventure that ends just when things get going. Innovation and pretty graphics make it a force to reckon with, even if its brevity is an issue.

As Darth Vader's secret apprentice, you're tasked with exterminating the last members of the Jedi order. You do this by honing your force powers and scouring the galaxy for those in hiding. Each level takes an on-rails approach, moving you along automatically once you've cleared the immediate area of enemies. Force powers are the only way of doing so. Thankfully, you're given quite an arsenal of abilities to get the job done. A mixture of offensive and defense force powers are triggered by drawing designated shapes on the touchscreen.

Force Grip, for example, has you draw a downward loop starting on the left side of the screen. Icons above an enemy's head signify whether you're in range for your selected force power and whether it'll work. You switch powers by tapping and sliding two fingers on th screen. For instance, changing to Force Lightning from Force Grip involves swiping two fingers to the right.

Tracing shapes on the touchscreen comes closer than any previous Star Wars game to making you feel as though you're actually using the power of the force. The innovation here can't be understated - it's bigger than Jabba. Deflecting blaster fire with diagonal flicks whilst drawing quick downward loops to pull Stormtroopers in for a quick slash with your blazing-red lightsaber is challenging and exciting.

Six chapters round out the story, giving you about an hour of play time. It's all over too quickly. The short chapters are to be appreciated, since they can be played in a matter of minutes on the way to work or while in wait, but more missions would have added greater value and fleshed out the story further. Entire narrative sequences, locales, and even characters have been omitted, leaving the story threadbare.

Of course, you're allowed to replay any previously completed mission and there's also a Survival mode set within each of the chapters that pits you against waves of Imperial foes. These might get you playing an extra 15-20 minutes, but they're not compelling enough to add hours more gameplay. You could spend slightly less for two hours at the movies (or two minutes watching this video of The Force Unleashed).

Value for money is ultimately where The Force Unleashed falls short on iPhone. While its gameplay is as entertaining here as it is on any other platform, it's short-lived and cuts out too many elements related to the story. Like Greedo, it suffers from an abrupt ending to an interesting adventure.

Not for you? Check out our buyer's guide to the best iPhone games yet.