I am not sure this is the same for every case, but I noticed that when I pressed any button, the game takes up to 0.5 seconds to respond. But when I decreased the resolution on my windows 7 laptop, and decreased the window size of the unturned game, the input lag was reduced to about less than 0.1 seconds delay. I hope this helps the people who are suffering from similar problems on their computers. Apparently, the higher the resolution, the more the computer struggles to keep up with keyboard input because it is too busy updating the resolution to do anything else. But the less the resolution, the higher the performance. That was the situation with my laptop. The solution to the problem for similar cases: DO NOT PLAY GAME IN FULL SCREEN. Try to keep the screen size small.