I made a simple endless swing game for Android with Unity 5. It was my first experience with Unity or C#. I needed units for college, and I was able to have a professor oversee the project for 4 units. I'm so glad he did because I had a ton of fun making it!
Took a quatter to make and I'm pretty proud of it even though the only users nowadays are friends and family members who keep it installed and accidentally open it, and a couple of Russians :)