I played Kluster Krystals Megaclusters™ today, lost $30, didn't understand anything!
I dont either, I think I made close to 50 spins and it rarely hit but from what I've understand I think we need to trigger chain reaction to hit multiple symbol with the bonus symbol on the reel atleast 4 times to trigger the main bonus feature. If you trigger 6 times chain reaction without the bonus symbol on the reel, it will reward you with some other bonus round insteadPS: Still didn't have luck to win over x200! MT 2 don't like me, I got and bought a few bonuses and max win just x127! 
Try chaos crew instead. It has similar bonus feature with MT 2 and there is an event running for the slot
24 hour contest for Chaos Crew slot. Currently only 6 players has taken part in it, click on the image for direct link onto the event page
Well soon after my comment yesterday I had an amazing win:
San Quenting is a definitelly amazing slot that can give really high rewards!
And I play chaos crew, it's an interesting slot with "strange lines", I won their bonus a few times (from play) and I didn't get more than x50! I had higher wins from spins when I get those wilds with x2 and x3! Fat Rabbit is a very interesting slot for me, and I get that bonus from time to time, but usually I get just to the second level, once I got to the third level...
I saw that we need some chain reaction, but I didn't get more than one reaction... I will try it again, but before that I will check paytable! I like to play slot and how I play I learn about it, but for some slots it's recommended to check that before playing!
New day, new victories! Good luck all!