The objective of Survive The Glass Bridge is to reach the other side by selecting the appropriate glasses. Due to the fact that one of the two glasses on the platform is made of thin glass, it is unable to support the weight. This is the reason why you will fail. To tell the difference between the two glasses, you'll have to look very closely. Changing the difficulty level from the main menu will alter your ability to distinguish between the two glasses, if that is something you wish to do. Furthermore, if you do not make it to the opposite side within the stated time limit, the game is considered to be lost.