Here are a couple of normal idea in a column
Boomerang
Fidget Spinner
add the crab
jetpack
ebay or amazon
cars
Complex ideas:
hats (with buffs)
advanced cooking
Uno (yes the card game)
generators (like the cobblestone generator but for more things)
Gym (get permanent buffs after working out)
Cookie clicker (idk)
potion effect mobs (like the stray, husk, bog(now) just more mobs that when they hit you give you a potion effect)
These were off the top off my head. hope these help :D
