Red Sun Beach Escape

You and your friends have decided to spend the weekend at the beach. You go to the Red Sun Beach and very unusually you do not see other people at the beach. You just ignore this and start to play and have fun there. After sometime, you all lie down to get some rest. A while later, you wake up and do not find your friends around. After searching for a while you assume that they must have gone inside the lighthouse and so you make up your mind to go there and join the group. It sounds a bit strange but you must solve a series of puzzles before entering the lighthouse.