Nice try, but there are some things you could try to improve your game:
- First, try adding a main menu with the instructions of your game, a play button and maybe credits if you want.
- Second: using music could add more life to the game while you're playing. Try using the Audio System in Unity. It isn't complicated and there are plenty of tutorials!
- Third: bird could have a little of random movement. If you don't move the pipes from the start, you can make infinite points without a single key press. It would be great if you manage to force the player to actually having to move the pipes.
Fourth: Try moving the background for a graphic sensation of advancing in the world.
Keep working! Cheers!