;outside main loop
EndTime=Millisecs()+900000
;inside main loop
TimeRemaining=(EndTime-millisecs())/1000 ;in seconds
MinutesRemaining=TimeRemaining / 60 ;in minutes
Seconds=TimeRemaining Mod 60 ;in seconds
text 0,0,MinutesRemaining+":"+Seconds
If Millisecs()>EndTime then EndGameFunction()
EndTime=Millisecs()+900000
;inside main loop
TimeRemaining=(EndTime-millisecs())/1000 ;in seconds
MinutesRemaining=TimeRemaining / 60 ;in minutes
Seconds=TimeRemaining Mod 60 ;in seconds
text 0,0,MinutesRemaining+":"+Seconds
If Millisecs()>EndTime then EndGameFunction()