There’s another angle the author didn’t touch on. Nintendo is gating this content not only behind the purchase of amiibo, but they’re also making it inaccessible to anyone who has a pre amiibo 3DS model. So for them this ends up being not a $15 price for content, but actually closer to $200.
I’m not personally bothered, because Metroid for me isn’t a game I play for an exacting mechanical challenge. These games normally don’t have hard modes and I’m fine with not having a hard mode in this one either. But for anyone who does feel like this stuff is important, they’re really kinda out of luck if they got on the 3DS train early.
A game supports as many existing Amiibos as possible
The functionality is fun but mostly cosmetic
Amiibos stink when:
A game requires a specific line of Amiibo, which only support that game and vice versa
Major content is locked behind them
To me, the selling point of Amiibos is that you can grab one of your favourite character and be assured that it’ll add a little something themed around that character to lots of different games (Mario Maker and Yoshi’s Woolly World are good examples of games that supported Amiibos this way). Having to buy an Amiibo as physical DLC that only affects a single game is the total opposite of that and I have no interest in it.