Space Shooter (... or, Galaxy Shooter?)
Unity
I started learning Unity game development and made this little quasi-Galaga clone thing. The short, repetitive music will drive you insane after a very short time. Beware! (Don't forget that you can right click on a tab and "Mute site" in Chrome.)
WSAD or arrow keys to move. Space to shoot. Ship wraps horizontally a la Pacman. Enemies worth 50 points. Shield looks like an egg.