-Got a lot of coins but nowhere to spend them? Go to the store area and start buying stuff. Purchase gems so that you can stick them inside of your weapon and armor slots for extra statistical boosts, or purchase drill screws if you have enough gems and if you have a weapon that you love with no slots, and want to stick some gems in it.
-Go to the box area and you can purchase a pet egg to get a pet, or purchase various fighter boxes. The bronze box is worthless (you earn bronze fighters anywhere) but the silver box has some powerful fighters in it.
-The most worthwhile expenditure of gems (arguably) is in expanding your backpack, so that you can have three or even four pages of items. Three pages costs 50 gems and four pages costs another 100 gems.
-Upgrade any fighter massively by fusing three of the same fighter together. An easy way to get identical fighters? Sweep the same stage over and over and over again until you have three of the same fighter. Then fuse them.
-If you just want to load up on extremely fast experience points, then set the sweep to sell every piece of loot that you pick up. You won’t really pick any rare loot up anyways, usually, so nothing to worry about. You’ll just end up with tons of coins and tons of experience.
-Take advantage of all of the free stuff that you unlock as you gain levels. For example, the meditation room is the first one. Mercenaries will allow you to hire your fighter out, or hire someone else’s fighter.
-The World Tournament (another unlockable) is a great way to win coins. Just like March Madness, this allows you to fill out your brackets and bet on the contestants.
-The Secret Shop isn’t an unlockable, but you can take the reputation that you earn from meditations and disrupting other people’s meditations, and go spend it there for good weapons and armor, and other bonuses.
-Once you get a pet, take it to the pet house and feed it as often as possible in order to teach your character new skills (AKA stat boosts, usually). Open up more pet food bowls to train it faster.
-The only way to get VIP is by purchasing diamonds in the store, usually. However, whenever there are events that allow you to claim free diamonds, they will all go towards your VIP level, allowing you to get VIP benefits for free.
-Visit the Fortune Cat every so often in order to get extra bonuses. Some of them cost diamonds, and some of them require you to have a VIP level, but many of them are free as well, and they change at all times.
-Different types of fighters can equip different types of equipment, but if you want to cheat and give a fighter equipment that s/he can’t normally use, switch to a fighter who can equip it. Then equip it and switch back to the previous fighter, and it will still be equipped.