Develop simple game

I would like to develop a simple online game for children. The game will ask a question and the child must answer within a certain amount of time. There should be 2 kinds of questions available: 1) Ask a simple question and the child answers – e.g. the question is 1+1 and the child needs to enter "2" 2) A multiple choice question where the child chooses the answer e.g. the question is 1+1 and there are 4 answers 1,2,3,4 and the child must choose 2 I should be able to add new questions and change the time allowed for each question. There should be a prize system for right/wrong answers. Each time they answer a question or a certain number or questions right pictures/icons should appear (such as a picture of a trophy or something like that). I should be able to add pictures (prizes) and decide how many answers need to be answered correctly in order to get an icon. If they get an answer wrong then they should lose icons. I am open to other ideas if you have any. It doesn't matter which program is used to build the games but I need to be able to add questions etc