First, let me start by saying that zombies terrify me, and that the space zombie necromorphs from the Dead Space trilogy pretty much make me into the world's biggest coward. That being said, I've already played through this installment three times, which should be the first big note on how I feel about this game; for someone like me to be so drawn in by the gameplay that I'd willingly face the necromorph horde time and time again means that Dead Space 3 got a lot right.
The necromorphs get marginally less scary in this game compared to Dead Space 1 and 2 by virtue of the new crafting system. A lot could be said about it, but what quickly became the most appealing to me was that I could, (once the right parts were found and experimented with) design weapons that fit my individual play style to a "t". There are tons of YouTube videos and article about what the 'best' DS3 guns are, but in truth, you'll play and find something that works remarkably well for you. For guys like me who love the having some flexibility on panic fire, weapons that compliment keeping bad guys at range and shooting in a large spread quickly tend to be at the heart of my designs; for others, ammo conservation with maximum power per shot works better for them since their nerves are steadier. Regardless of your play style, you can count on investing time and energy finding what works for you in any given situation, and devising tactics that support it. This element makes this installment much more addictive than the previous two games, since you have so much more power in your own hands to make your dream offense a reality.
In the end, even if you're like me, (terrified of zombies = this guy) you'll still willingly face down the hordes to find your next upgrade while giggling maniacally despite the horrors you face with your chosen arsenal in-hand.
The game also continues on from the story from Dead Space 2, so fans from the first two games will have a better idea of who the major characters are, and the arc of the story will feel better than it would to someone who's joining the series for the first time. I played through the first two games, so I found the main campaign and optional missions very satisfying in terms of expanding the universe and scope of the story. Your mileage may vary though, if this is your first Dead Space game, as you'll be playing catch up on the relationships of the main characters.
The only tricky thing to watch out for is the new save system; instead of manually saving at consoles like you did in previous games, this game works with an auto save feature. This happens at Progression Saves, (points where the story advances) and Inventory Saves, (logging out, certain areas in the game.) Some players make like it, but for guys like me it kept me guessing on when the best time to exit out of the game was. The tricky part is that by logging out after having an inventory save but not a progression save is that you may have to do a tough section of the game over again with less resources, ammo, etc. in your inventory than the first attempt. Conversely, at certain points in the game it's possible to completely abuse the save system by farming goods, logging out, and then logging in and farming them again. So a little bit of caution is needed.
Other than that, I give this game major props; it's moody, atmospheric, and ridiculously fun. Definitely worth checking out!