Oh yeah, speaking of Amazon, Gravity Rush Remastered was Amazon-exclusive.
I'm not sure if it counts, but there were other weird ones that you could only get through Amazon because of how the publisher decided to distribute it... Items like Natsume's River City Rival Showdown, I think...?
I realize that's getting into the nitty gritty though of retailer exclusives, and that's a major pain. But I know I had originally missed Xenoblade Chronicles back in the day because I didn't know it was Gamestop-exclusive, and I'm sure others had missed out on Gravity Rush Remastered.