Kerala and Goa are both states of India. Both are tourist destinations.
And that's the end of similarities.
But if you love Goa because it's India, and you don't mind a few little local sillinesses to obtain alcohol - then there's a good chance you will enjoy Kerala.
(beer served in teapots on the beach)
It is very lovely, the backwaters are wonderful, and personally I really enjoyed an amazing overnight excursion to Cochin to see the famous dancers. And the fishing nets, and the market, and the riverside....
I really like that city, I will return one day.
Most time I stayed in Kovalam - the Uday Samudra hotel, which was OK, but not wonderful.
The beach was a working beach. You are woken each morning by the cries and songs of the fishermen as they haul their catch onto the beach. You can go help if you want.
The best, and "Memory for Life" bit of the holiday for me .
I'm glad I did this!
First Choice and normal standard Thomson have now dropped Kerala.
However the TUI company Hayes and Jarvis still offers it, and the excellent small company Mercury Direct also offer Kerala.
I'd not recommend Kovalam - maybe suggest Varkala is better, especially for Goa fans.
Major plus points for me - the Americans didn't find it yet - no McDonalds and similar junk food.
The local food is excellent.