Game is WAY too buggy at the moment to be even the slightest bit enjoyable. The first zombies I encountered not only flickered in and out of existence, they were invincible. Adding to the whole flickering business, every time my character shot, he'd phase as well. Fix the bugs, and you might possibly have a good game.
I found the game to be very responsive. A little laggy at points but never game breaking. And by no means is this a button-masher, if you do that, you'll lose rather quick...
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