Here are a few concepts I had for interesting ways to go about leveling up in the game. Gaining stats through mini games like in FFX were really great concepts so I played around with a few ideas of my own.
Idle clicker: The levels are represented by monsters you fight with the XP translating to damage dealt so after gaining enough XP you'd kill the monster and gain stats as loot
Coin pusher: monsters and other things will drop onto the tray and you can use your XP to try and push them off the edge.
Coin pusher alternative: The points you gain could be spent to buy furniture for your base camp that would increase your stats or weapons and so on.
FF rip off: basically FFX's lvl system but with the appearance of FFXIII's because I'm original.