transform alpha_dissolve:
    alpha 0.0
    linear 0.5 alpha 1.0
    on hide:
        linear 0.5 alpha 0
    # This is to fade the bar in and out, and is only required once in your script

screen countdown:
    timer 0.01 repeat True action If(time > 0, true=SetVariable('time', time - 0.01), false=[Hide('countdown'), Jump(timer_jump)])
    bar value time range timer_range xalign 0.5 yalign 0.9 xmaximum 300 at alpha_dissolve # This is the timer bar.