Lara Croft: Relic Run

Oh the grind is real on this one. It's been reported that ammo drops and free spins do not count towards this, as it clearly states "during runs." That means you only get what you pick up during the runs. The only way to make this a bit faster (and still not by much) is to upgrade your Coins perk (so you get max money during your runs) and to beat the bosses, who give out money after you kill them. It's a long grind though.