saving space on iphone 4s by sending to icloud?

Ok guys bear with me I am new to the iphone and still getting used to all the many features...add that to the fact that I am an oldie...and you have a recipie for disaster 🙂 Ok here is what I want to do...how do I do it? I have downloaded a game and I want to upload to icloud, thus removing from my iphone (and freeing up space as my iphone is only 8gb) I presume that when it is on icloud I can download again when I want to play it ie use icloud as a storage and create more storage on my iphone 4s...could you take me through the steps please...many thanks 🙂