How can I get a better view of the greens?
Toggle the left shift key to get a ground level view. Also you can zoom to the flag using the up arrow key and also you can use the c key to get a behind the pin view when you are on the green.

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Why do I only get around 60 percent of the power when I should be getting 100 percent power when I use the mouse swing method?
Try Turning the mouse setting acceleration to maximum in your mouse properties. Try improving the frame rates in the Menu under Graphic Options in the Playmail.

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Does the lie of the golf ball effect my shot?
Yes. You can check the lie of your golf ball by toggling the G key . If your golf ball is on a slope it will hook or slice naturally as in real golf.