But, as previously noted, there are some differences between the two offers. Though they sound similar--a $20 e-gift card at Walmart.com versus "$20 off a future video game purchase" at Amazon.com--those that pre-order from Walmart.com get their gift card immediately and can use it on anything sold by the online retailer.

Meanwhile, those that pre-order from Amazon get their credit "within 2 business days after the product ships"--Super Mario Galaxy 2 arrives May 23 in North America--and can only use their discount on "a future video game purchase." Then again, Amazon.com seems to be more timely with its product shipments and subsequent deliveries.

But as I've said before, it's a good deal regardless of the retailer--either way, you're getting roughly 40% of the game's $49.99 asking price back--just make sure to act fast, as there's no indication when either of these deals will end. Thanks MuteMode.