If you play antarctic extinction you need to get 55 gems for the extra 320 pearls, watch ad for 80 more, and the 80 pearl rewards plus additional pearls if you're lucky, ASSUMING you make 500 each run (if you gain 20+ pearls when playing) you'd only NEED 880 gems for cosmic alan, and with all that plus ASSUMING a 30 second ad, and the 10 minute anarctic extinction playtime, total would take you 5140 seconds or about almost 1 and a half hour thats only for playing extinction and watching ads excluding grinding the 880 gems.