Save the Green Planet! (2003)

AKA: 지구를 지켜라! (Jigureul jikyeora!)

Lee Byeong-gu believes he caught himself an alien. He keeps him locked up in his basement and subjects him to bizarre experiments to test his half-baked theory. It's a great concept although much of the runtime keeps you guessing. It's nevertheless a memorable oddity, which I found endearingly moving.

4 lunar eclipses out of 5