For those who don't know, GURPS planet Krishna is based on a series of SF books that are somewhat tounge-in-cheek parodies of the Mars books by Burroughs. I must give a warning: DON'T BUY THIS BOOK UNLESS YOU'VE READ THE STORIES.
That being said, it is a fun setting to play in. It's light. It's fluffy. It's been described as Space Opera by Gilbert and Sullivan. But the setting wears mighty thin, pretty quick.
Within a few weeks, my players were rolling their eyes. "Aw, man... why can't we play something else?" That's not good... you want your players to have fun, not view gaming as a chore.
The real joy of this book is that it exposed me to the original series. That is the real strength of this game... the setting it is based on.