I've bought this game from 3 different sources, and I have no regrets. This is one of the best games I have ever played- the awesome storyline, meeting arbitrary characters a few levels after you killed their father (what a shame) and the perennial need for strategy make this my favorite game. You could go in guns blazing, but you'd probably get slaughtered. Using your resources (BE, health and ammo) well is essential since it's easy to run out of one and end up in a near-death situation. I never played the game in a run and gun fashion, and I'm not too sure that can even be done, but my stealth based sniper/hacker destroyed pretty much everyone in my way. Of course, sometimes words are more effective than bullets- Sticks and Stones!
