I've been experimentally learning C# in Unity and decided to have an endgame with my learning.
Enter Space Ace. A space shooter with 20 waves, 4 unique enemies, 10 unique enemy formations, powerups, a shield, homing missiles.
If you want a satisfying experience that takes up no more than 5-10 minutes of your time (get your mind out of the gutter), give it a look-see!