At first thanks for the comments and the recommendations. I will take them into consideration.
on a fail situation there are 3 kind of alarms:
i) a sad tone
ii) a vibration (almost every mobile phone supports this)
iii) the displaying of the remaining lifes in place of the score for 1-2 seconds.
However, maybe you are right that some kind of a blinking graphic around the player would trigger more attention on what bad happened and perhaps I will include it on a next version.