To make the game less plain and boring, there could be random events happening
on the maps, that if the player participates, the player gains rewards upon finishing it.
Random events could be like… An npc walks in the grinding area you are, and asks the players to
gather a certain number of an item that drops from a monster that spawns on that location,
monsters could begin spawning like crazy and you would need to reduce their
number, a village could be attacked by monsters and you would need to defend the npcs,
a boss appears on the field, and you must stop him before it reaches the portal to the town.
There are several kinds of events you guys could do to make the game grinding be
less boring and with more things to do while playing.
Also, try not to make the system greedy and rewarding only the one who did best on the event,
plus, not make the events very frequent.