Fine selection
The biggest problem is not being able to choose what game to play. It's random. Without that choice, some games are jarring to play until you figure it out. Not that we need tutorials, but the list on the app store page made me think there would be a list to choose from. If I want to play a specific game, the only way I've found to do so is hit the "next game" icon over and over again until I find it.
