There is always room to expand a game. Try now to add more conditions or why not change the timer to display total distance. Add more varied obstacles or different shapes, sizes, and speeds. Add more varied effects and a start screen and a game-over screen.

We can always add more and more. What one has to keep in mind is not to overly complicate the game such that players get confused or frustrated. Also, time and resources can be limited, and the more you add, the more the platform will need to handle, and the more the bugs that can be introduced. The more we add, the more the game's release will be delayed, and if we never stop adding more content, mechanics, and features, our game may never ship!

This is why it is very important when first designing our game to ensure that we know what its main pillars are; otherwise, we could get ourselves into a situation that is known in the professional gaming industry as feature creep, whereby one keeps adding more and more...