If the sales figures are to be believed, then this game has been overlooked by the vast majority of the games playing public which is a real shame.
Grin (the developer) have done a good job with this and although the pacing can be a tad slow at the beginning, the overall game is a polished product and highly playable. Combat is supremely satisfying (although the tinny gun sound for the pistol is disappointing) but some of the more meatier weapons are definitely up to the task at hand. Where this game really excels though is in the use of the bionic arm. At first it seems unwieldy and hopelessly inaccurate but after an hour or two, you'll be amazed with how competent you'll become with it and you'll be grappling rock faces, ripping trams apart and throwing cars and enemies to the floor with consumate ease.
Technically, the game is also very nice and runs on Grin's own Diesel engine which must be commended for a smooth framerate and zero screen tearing. The soundtrack that accompanies the game is also excellent and the sound effects are nicely done (the deep robotic noises the Mechs make are particularly haunting.)
To summarise then, I'd say this really is a shamefully overlooked game and well worth a punt especially now its available at a cheaper price. Highly recommended.