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(+2)(-3)

Okay first thing is one of my favorite games
2. The first code is 213121
Remember that this is a second game to the original game and also a quick search can get a result
I managed 8 of 11
And I don't want to ruin everyone, but there are answers in the comments so if you Want, you will see there.

I don't understand how I'm supposed to get the first code though. 

(+1)

You get the code from the lines in the bar code