Starship Self Destruct

Based on a program I originally wrote for the ZX81
Can you find the code before it destroys your mobile?
You have 60 seconds to set the correct 4 digit code on the bottom level, by scrolling the numbers up and down. Press to set the number and try pressing the deactivate button, to see if it stops the count.
A hint is on the about screen.
Not a great explosion, but this is the 1980's!
Just a bit of fun.
There are no ads or payment required, just try it.