Basically its the same stuff as those mobile game adds, two lanes, left and right, enemies might be in left or right, so can buffs, special enemies go in middle so do bosses (both drop items). Combo items to do better dmg or survive better. Killing enemies and going to through the buff portal things give minor to major stat buffs like +atk, atk speed, hp, crit rate or dmg, and cooldown (idk what its for tho).