Use your coins to push other coins. Do not drop too many in at once. Instead, go slow and allow your coins to push others on the bottom level into monster slots. After earning Friend Coins by using your friends' monsters in battle, summon monsters with them. There is a chance you will get a rare creature. Complete Lily's quiz to easily get a large number of gold coins. Save your rainbow coins for when you need the best and rare monster summons. Because there is no time limit, take your time when dropping coins. Drop a few coins until there are two or three coins remaining for a monster to attack and wait to see what happens. Normally, a number of attacks will be triggered, more coins will fall, and you can take out the monsters easily without taking damage. Enter the Shop and watch the advertising videos for free coins and other bonuses.