def enter():
    gfw.world.init(['bg', 'monster', 'unit', 'unit', "gameclear"])
    Monster.load_all_images()
    Unit.load_all_images()
    life_gauge.load()
    gameclear.load()

    global selectedUnit

    if load():
        unit = gfw.world.object(gfw.layer.unit, 0)
    else:
        unit = Unit(1)
        selectedUnit = unit
        gfw.world.add(gfw.layer.unit, unit)
        gfw.world.add(gfw.layer.unit, Unit(1))
        gfw.world.add(gfw.layer.unit, Unit(1))
        gfw.world.add(gfw.layer.unit, Unit(1))

        bg = gobj.ImageObject('background.jpg',
                              (canvas_width // 2, canvas_height // 2))
        gfw.world.add(gfw.layer.bg, bg)

    magic_circle = gobj.ImageObject(
        'magic.png', (gobj.magic_circle_pos[0], gobj.magic_circle_pos[1]))
    gfw.world.add(gfw.layer.bg, magic_circle)

    global font, font2
    font = gfw.font.load(gobj.RES_DIR + '/Sweet_story.otf', 50)
    font2 = gfw.font.load(gobj.RES_DIR + '/ConsolaMalgun.ttf', 20)

    global monster_time
    monster_time = 1
    global monster_level
    monster_level = 1
    global monster_level_up_time
    monster_level_up_time = 50
    global unit_time
    unit_time = 50

    global music_bg, end_music
    music_bg = load_music('res/Track 5.mp3')
    music_bg.set_volume(10)
    end_music = load_music('res/Track 26.mp3')
    end_music.set_volume(10)
    music_bg.repeat_play()