Pft. Who needs codes when you have fingers?
Just feel the bags for the specific pieces. If you collect the lego/mega blox ones you would know. Furthermore, Lego has 16, Mega blocks has 10-ish different figures in a case, while this has only 6.
Pieces to look out for : Sunstorm's wings, Crankstart's pipes, Spinester's rotors...
As for the rest, do the "elimination" method where if it has a piece that does not belong, it's not it, and try to guess the rest of the parts. This could be harder than lego due to the amount of pieces, when lego only has hat+head+body+leg+weapon ... But hey, 6 figures opposed to 16.
Codes are nice too... I'm sure hasbro deliberately put em on there, seeing how each has a specific instruction manual.