- Get a *Number object*  (Objects/Special objects/Number objects)
- Get a *Counter object* (Middle/Flag-Counter-Random)
* Change Mode to “Range”, Count range to 0-whatever max number you want, Count timing to “When not 0” [to count down].
* Connect it to the Number object
- Get a *Constant object* (Input/Constant)
* Change Output value to .01 [so it counts down slowly)
* Connect it to the Counter object
- Get a *Comparison object* (Middle/Comparison/=)
* Connect it to the Counter object
- Get a *Constant object* (Input/Constant)
* Connect it to the = Comparison object
- Get a Retry object (Output/Retry game)
* Connect it to the = Comparison object

Tip: Press play to test it out at different stages to see what it does