simple-frog-game-in-which-cars-only-go-one-way the game
A downloadable game for Windows
This game was made in one hour. The details can be found here: https://www.reddit.com/r/gamedev/comments/6obfrm/game_improv_could_i_have_a_topi...
Edit: The Mac version was deleted because it did not work.
I had some trouble getting the roads to move quite right for the loop to work infinitely. You'll notice the roads start to get a gap between them. What's happening is that rather than move your character up, I move the roads down and have them loop to the top when they hit the bottom of the screen. They move only when the frog plays the animation to go up, so I tried to time the length of that animation and their speed in such a way as to allow it to loop infinitely, but when that didn't quite work, I made the road bump down if it was too high up.
I realize now that I could have made the animation end when the y value of the frog and road were equal. This would stop your character from moving up at all, but with flags and some commands about not overlapping the road, I could've fixed that. Ah well, I only had an hour.