(Sorry for posting so rapidly but i have A LOT of ideas!) How about a gold exchange, you can sell 50 gold for 200 fame and (buying gold with fame should cost higher, just to be fair) and you can buy 50 gold for 500 fame (this time I will not ask to + this idea, this is just an idea)
Following @Jacoby2000's idea, how about adding a food dungeon where some monsters drop some food. The dungeon can be called "Food Forest" with a forest-y area. + is you agree. (And i am not a + w[h]ore)
How about a daily bonus? We can get things depending on how many consecutive days we play. For example, on day 1, we can get a sucky item like a T0 ring or 10 bonus exp. The rewards should be getting better depending on how long we will play. You can claim rewards in the gift chest in vault. And i dont really care if the daily bonus (if you are going to add) is a different class than mine. For example, i am a rouge and the consecutive day bonus gives me a T8 sword. I'm cool with that. Press the + button if you like this idea! (P.S This is a way to earn equipment but at a slow rate guys!!!)
When i put extreme mode with perma-gun and spam the gun, the next level just lagged so much, it froze. This is not a bug report, this is just a tip not to make ur computer lag so much :P
How about a "Witch" who can make enemies into allies for a few seconds. The witch can use a wand or staff. The special can be called a vial (sort of like a potion container) and throws it like poison or a trap. The range and duration of enemies turning into allies depends for the T of the vial. Rate This however you want. 999999999/5 stars for this game btw!
How about in sandbox, there is a "spawn egg button, killing yourself and spawning another one of you. The baby has everythi9ng that the adult had but is smaller and you keep your score.