Unlockable Rewards

Maybe add a small reward for players when they get all the golden cards for a certain group or tier of group, like if you get all the golden item cards, all towers get plus 5% item and quality chance, if you get all golden potion cards, all unique potions can be dropped multiple times with diminishing chances, first drop 5%, second 4%, third 2.5% etc. And maybe if you get all golden cards maybe give towers a golden glow or maybe a reward like a legendary tower that throws gold. Last idea was off the top of my head. Please let me know what you guys think. Cheers!

I dont think a bonus for towersis a good idea.having a legendary already makes for a big gap in survival time. But maybe it would be a good idea to give a bonus on legendary drop chance when having all golden cards in one kind of cards. A lot of people are not heading for maximum survival time because they want to wait for all legendarys because then your survival time goes up alot. So everyone is just doing daily quests

Ok, how about if you get all normal golden cards you get an increase in legendary drop rates, then when you get all golden cards you get a Legendary card that has a unique ability. If there are legendary cards on the field, you get a bonus 25% attack speed per legendary, for 8 seconds, cooldown 180?