What is this weird screen ? (CGB - Super Mario Deluxe )

I got one "Super mario deluxe" CGB cart.

When it boot on my GBA SP , it display this weird screen :



Sorry for the poor quality , but it is displayed for only few second...
It says :

"Aaaraaaaaa.CEDEFBD.X THANK YOU"

and then the game start !

here is a pic of the cart :



What the hell is that weird boot screen ? :-0

 

It means game boy advance sp it incompatible with game. Odd in some of the gba sp's the backwards compatibility seem to be off or non existent.

 

It's an unlockable feature in the game, to make your own boot screen . You can change/edit it in the options menu of the game... aaah the memories hehe

 

Wow Thank you for the info ! can u remember how to change it ?


EDIT: I found it ! Thank you !