Enter codes at the main console in the Batcave. Note: These codes only make the items available for purchase. You'll still need enough studs to buy them.

Effect	Code
10X Stud Multiplier	A92HDW
2X Stud Multiplier	74EZUT
4X Stud Multiplier	EY2B5C
6X Stud Multiplier	HYF2B7
8X Stud Multiplier	4H9HQE
Big Heads	GTDHR3
Invincibility	MVXP8E
Regenerate Hearts	ZXEX5D
Stud Magnet	MNZER6