Best game in a while

I just get pissed of by this game, ive found all three batteries, opened the briefcase, found the safe, found the code to the safe, but no matter how i input the code it wont open. >;/
 
Either this is some elaborate hoax to fuck with idiots like me, or I just totally suck at this game, because I can't figure out how to open the briefcase :/

Edit: OK, it's not a hoax. But i give up...
 
Fuck this, lost all patience after finding 4 items and not knowing wtf to do next. I want to urinate in the corner but the game doesn't allow me to do it sooo... I'm gonna go urinate in the toilet now instead.. and fuck that game!
 
I give you a hint on the left box: Pianokeys start from C

edit: that wasn't so hard after all, took me a little over an hour to get to this:

sagrario.png