Intro game in python

game.py

treasure = 0

def get_input(string):
    print(string)
    user_input = input("> ")
    return user_input.upper()

def end_game():
    if treasure > 0:
        print("You got " + str(treasure) + " treasures!")

    print("Game is over.")

def start_game():
    print("welcome to the game!")
    room1()

def room1():
    print("You find yourself in room #1.")
    decision = get_input("You see a DOOR and a WIN")
    if decision == "WIN":
        print("You win instantly. What a challenging game!")
        end_game()
    elif decision == "DOOR":
        room2()
    else:
        print("That's not an option in this room.")
        room1()

def room2():
    global treasure
    print("You're now in room #2")
    decision = get_input("You see a DOOR back to room #1, a treasure CHEST, and a HALLWAY")
    if decision == "DOOR":
        room1()
    elif decision == "CHEST":
        treasure = treasure + 1
        print("You now have " + str(treasure) + " treasure(s).")
        room2()
    elif decision == "HALLWAY":
        room3()
    else:
        print("You remain in room #2")
        room2()

def room3():
    print("You are now in room #3")
    decision = get_input("You see an EXIT and a HALLWAY back to room #2")
    if decision == "EXIT":
        end_game()
    elif decision == "HALLWAY":
        room2()
    else:
        room3()

wants_to_play = get_input("Would you like to play a game? Input y or yes. ")

if wants_to_play == "Y" or wants_to_play == "YES":
    start_game()
else:
    end_game()