So, I've completed the first level.
The introduction is pretty amazing. The best on iOS yet.
The voice acting is phenomenal. It's really, really good and Slade is voiced perfectly.
Graphically, this the best on iOS. Better than Infinity Blade, considering everything going on. It's a real treat.
Although there are a couple of little things I was hoping to see:
The explosions are a little underwhelming.
The lighting doesn't seem to be dynamic (doesn't change, when under shade for example)
Your character doesn't cast real time shadows, nor leave bullet impressions on the environment. These observations are merely meant as a graphical immersion analysis.
These are small niggles, in an overall stunning game for iOS specifically. Considering the platform, as a whole, really needs more titles like Shadowgun - I am, overall, highly impressed and can recommend the game to any action, shooter or adrenaline enthusiast.
A side note, I was rather surprised to see little hacking puzzles, which remind me of Mass Effect thrown in.
A nice touch, indeed Madfinger