Easily the #4, you just follow one of the Unity tutorial about making an Endless Runner and you are done.
#1 is not difficult the graphics / controls/ logic, but the hundrends of players, you need to have a solid network infrastrutures to avoid strange behaviours between server and client. It is not easy managing more than a couple of players, and hundrends of players are vastly more difficult.
#2 UI driven it is relatively easy making the graphics, but you need some coding experience having some knowledge of patterns you are familiar to manage UI events, or you are going to write spaghetti-buggy code really fast after you are going to implement the 3rd sub-window.
#3 actually it should not be too difficult, but I think coding is a must, because no tutorial can give you all the possible cases you need to implement the rule of you game, in case you are not making a solitaire game.