public void LoadContent(ContentManager Content, GraphicsDevice graphicsDevice)
{
BtnTest = new Button(new Vector2(10, 10), 100, 40, 0, Color.Black * 0.15f, Color.YellowGreen * 0.15f, Color.White, Color.White, "Testing...", @"Fonts\StartMenuButtonFont");
ChallengeSelectionList.Add(BtnTest);
guiSystem.Add(ChallengeSelectionList);
guiSystem.LoadContent(Content, graphicsDevice);
}